generic: Convert incorrect generic/5.15 patches again

OpenWrt's developer guide prefers having actual patches so they an be
sent upstream more easily.

However, in the case of hack-5.15 patches which are not meant for
upstream, adding proper fields allows for `git am` to properly function.

This commit tries to rectify that, by digging in the history to find
where and how it was first added.

Signed-off-by: Olliver Schinagl <[email protected]>
Signed-off-by: Daniel Golle <[email protected]>

target/linux/generic/backport-5.15/733-v6.3-18-net-ethernet-mtk_eth_soc-add-support-for-MT7981.patch

@@ -1,3 +1,20 @@
+From f5d43ddd334b7c32fcaed9ba46afbd85cb467f1f Mon Sep 17 00:00:00 2001
+From: Daniel Golle <[email protected]>
+Date: Sun, 19 Mar 2023 12:56:28 +0000
+Subject: [PATCH] net: ethernet: mtk_eth_soc: add support for MT7981 SoC
+
+The MediaTek MT7981 SoC comes with two 1G/2.5G SGMII ports, just like
+MT7986.
+
+In addition MT7981 is equipped with a built-in 1000Base-T PHY which can
+be used with GMAC1.
+
+As many MT7981 boards make use of inverting SGMII signal polarity, add
+new device-tree attribute 'mediatek,pn_swap' to support them.
+
+Signed-off-by: Daniel Golle <[email protected]>
+Signed-off-by: Jakub Kicinski <[email protected]>
+
 --- a/drivers/net/ethernet/mediatek/mtk_eth_path.c
 +++ b/drivers/net/ethernet/mediatek/mtk_eth_path.c
 @@ -96,12 +96,20 @@ static int set_mux_gmac2_gmac0_to_gephy(

target/linux/generic/hack-5.15/750-net-pcs-mtk-lynxi-workaround-2500BaseX-no-an.patch

@@ -1,3 +1,16 @@
+From 880d1311335120f64447ca9d11933872d734e19a Mon Sep 17 00:00:00 2001
+From: Daniel Golle <[email protected]>
+Date: Mon, 27 Mar 2023 18:41:54 +0100
+Subject: [PATCH] generic: pcs-mtk-lynxi: add hack to use 2500Base-X without AN
+
+Using 2500Base-T SFP modules e.g. on the BananaPi R3 requires manually
+disabling auto-negotiation, e.g. using ethtool. While a proper fix
+using SFP quirks is being discussed upstream, bring a work-around to
+restore user experience to what it was before the switch to the
+dedicated SGMII PCS driver.
+
+Signed-off-by: Daniel Golle <[email protected]>
+
 --- a/drivers/net/pcs/pcs-mtk-lynxi.c
 +++ b/drivers/net/pcs/pcs-mtk-lynxi.c
 @@ -92,14 +92,23 @@ static void mtk_pcs_lynxi_get_state(stru

target/linux/generic/hack-5.15/795-backport-phylink_pcs-helpers.patch

@@ -1,3 +1,20 @@
+From 027586ae8ecacff49757ed854c020f35d24a599c Mon Sep 17 00:00:00 2001
+From: Daniel Golle <[email protected]>
+Date: Sat, 11 Mar 2023 03:44:41 +0000
+Subject: [PATCH] generic: backport some phylink helper functions
+
+It isn't feasible to literally backport all upstream phylink_pcs changes
+down to Linux 5.15: It's just too many patches, and many downstream
+drivers and hacks are likely to break. We are too close to branching off
+to risk this, and it's also just too much work.
+Instead just add helper functions used by modern PCS drivers while keeping
+the original functions instact as well. While this may add a kilobyte or
+two of extra kernel size, it has the advantage that we get the best of both
+worlds: None of the existing codepaths are touched, but yet we have the
+option to backport singular improvements to Ethernet drivers where needed.
+
+Signed-off-by: Daniel Golle <[email protected]>
+
 --- a/include/linux/phylink.h
 +++ b/include/linux/phylink.h
 @@ -584,10 +584,37 @@ int phylink_speed_up(struct phylink *pl)