mediatek: remove redundant patch

The patch 921-mt7986-add-mmc-support.patch introduced by commit
dabcaac443 ("mediatek: add mt7986 soc support to the target") has never
been applied in a way that it would have any effect as it actually
created a file target/linux/generic/patches-5.15/... in the kernel tree
and was probably a patch intended to be applied to openwrt.git instead
of being put into kernel patches folder as a file.

As an upstream commit from vanilla Linux also adding support for MT7986
to the mtk-sd driver has already been included we can remove that old
patch.

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

target/linux/mediatek/patches-5.15/921-mt7986-add-mmc-support.patch

@@ -1,47 +0,0 @@
-From 0f8a0dd620b2fb5f9c852844ce5f445bb0bd6d52 Mon Sep 17 00:00:00 2001
-From: Sam Shih <[email protected]>
-Date: Wed, 4 May 2022 10:27:43 +0800
-Subject: [PATCH 5/5] mediatek: add mt7986a mmc support
-
-Add mt7986a boot mmc support
-
-Signed-off-by: Sam Shih <[email protected]>
----
- ...-mmc-mediatek-add-mt7986-mmc-support.patch | 31 +++++++++++++++++++
- 1 file changed, 31 insertions(+)
- create mode 100644 target/linux/mediatek/patches-5.15/0704-mmc-mediatek-add-mt7986-mmc-support.patch
-
---- /dev/null
-+++ b/target/linux/mediatek/patches-5.15/0704-mmc-mediatek-add-mt7986-mmc-support.patch
-@@ -0,0 +1,31 @@
-+diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
-+index 1ac9201..a32349c 100644
-+--- a/drivers/mmc/host/mtk-sd.c
-++++ b/drivers/mmc/host/mtk-sd.c
-+@@ -540,6 +540,18 @@ static const struct mtk_mmc_compatible mt7622_compat = {
-+ 	.support_64g = false,
-+ };
-+ 
-++static const struct mtk_mmc_compatible mt7986_compat = {
-++    .clk_div_bits = 12,
-++    .hs400_tune = false,
-++    .pad_tune_reg = MSDC_PAD_TUNE0,
-++    .async_fifo = true,
-++    .data_tune = true,
-++    .busy_check = true,
-++    .stop_clk_fix = true,
-++    .enhance_rx = true,
-++    .support_64g = true,
-++};
-++
-+ static const struct mtk_mmc_compatible mt8516_compat = {
-+ 	.clk_div_bits = 12,
-+ 	.recheck_sdio_irq = true,
-+@@ -584,6 +596,7 @@ static const struct of_device_id msdc_of_ids[] = {
-+ 	{ .compatible = "mediatek,mt2701-mmc", .data = &mt2701_compat},
-+ 	{ .compatible = "mediatek,mt2712-mmc", .data = &mt2712_compat},
-+ 	{ .compatible = "mediatek,mt7622-mmc", .data = &mt7622_compat},
-++	{ .compatible = "mediatek,mt7986-mmc", .data = &mt7986_compat},
-+ 	{ .compatible = "mediatek,mt8516-mmc", .data = &mt8516_compat},
-+ 	{ .compatible = "mediatek,mt7620-mmc", .data = &mt7620_compat},
-+ 	{ .compatible = "mediatek,mt6779-mmc", .data = &mt6779_compat},