gemini: dir685: Restore graphics

One of the v4.19 patches had a bug, this is fixed upstream,
but in OpenWrt we can fix it by just fixing the bug in the
patch.

We also need to augment the config file to select the
CONFIG_DRM_FBDEV_EMULATION symbol.

This restores the display controller on the DIR-685 to
working state: penguin and graphics on the little screen
with default OpenWrt install.

Signed-off-by: Linus Walleij <[email protected]>

target/linux/gemini/config-4.19

@@ -146,6 +146,7 @@ CONFIG_DRM=y
 CONFIG_DRM_BRIDGE=y
 # CONFIG_DRM_CDNS_DSI is not set
 # CONFIG_DRM_DEBUG_SELFTEST is not set
+CONFIG_DRM_FBDEV_EMULATION=y
 CONFIG_DRM_GEM_CMA_HELPER=y
 # CONFIG_DRM_I2C_NXP_TDA9950 is not set
 CONFIG_DRM_KMS_CMA_HELPER=y

target/linux/gemini/patches-4.19/0008-ARM-dts-Enable-Gemini-flash-access.patch

@@ -1,7 +1,7 @@
-From 74631102645df8984acbdf67b731e4d437f27fed Mon Sep 17 00:00:00 2001
+From 928681e6b46cb70317f7721aae8435ea89fcfd80 Mon Sep 17 00:00:00 2001
 From: Linus Walleij <[email protected]>
 Date: Thu, 11 Oct 2018 20:06:23 +0200
-Subject: [PATCH 08/18] ARM: dts: Enable Gemini flash access
+Subject: [PATCH] ARM: dts: Enable Gemini flash access
 
 Some Gemini platforms have a parallel NOR flash which conflicts
 with use cases reusing some of the flash lines (such as CE1)
@@ -16,9 +16,9 @@ access.
 
 Signed-off-by: Linus Walleij <[email protected]>
 ---
- arch/arm/boot/dts/gemini-dlink-dir-685.dts | 35 +++++++++++++++-------
- arch/arm/boot/dts/gemini-sq201.dts         | 31 ++++++++++---------
- 2 files changed, 41 insertions(+), 25 deletions(-)
+ arch/arm/boot/dts/gemini-dlink-dir-685.dts | 33 +++++++++++++++-------
+ arch/arm/boot/dts/gemini-sq201.dts         | 31 +++++++++++---------
+ 2 files changed, 40 insertions(+), 24 deletions(-)
 
 --- a/arch/arm/boot/dts/gemini-dlink-dir-685.dts
 +++ b/arch/arm/boot/dts/gemini-dlink-dir-685.dts
@@ -84,15 +84,6 @@ Signed-off-by: Linus Walleij <[email protected]>
  				pinctrl-gmii {
  					mux {
  						function = "gmii";
-@@ -430,7 +443,7 @@
- 		};
- 
- 		display-controller@6a000000 {
--			status = "okay";
-+			status = "disabled";
- 
- 			port@0 {
- 				reg = <0>;
 --- a/arch/arm/boot/dts/gemini-sq201.dts
 +++ b/arch/arm/boot/dts/gemini-sq201.dts
 @@ -41,14 +41,12 @@