uboot-mediatek: update to 2021.10

U-Boot 2021.10 has been released.
Rebase mediatek patches on top of new release and remove some patches
which have been merged upstream.

Tested on Bananapi BPi-R2 (mt7623), Bananapi BPi-R64 (mt7622) and
Linksys E8450 (mt7622).

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

package/boot/uboot-mediatek/patches/410-add-linksys-e8450.patch

@@ -336,14 +336,14 @@
 +};
 --- a/arch/arm/dts/Makefile
 +++ b/arch/arm/dts/Makefile
-@@ -1007,6 +1007,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += \
+@@ -1104,6 +1104,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += \
  	mt7622-rfb.dtb \
  	mt7623a-unielec-u7623-02-emmc.dtb \
  	mt7622-bananapi-bpi-r64.dtb \
 +	mt7622-linksys-e8450-ubi.dtb \
  	mt7623n-bananapi-bpi-r2.dtb \
  	mt7629-rfb.dtb \
- 	mt8512-bm1-emmc.dtb \
+ 	mt8183-pumpkin.dtb \
 --- /dev/null
 +++ b/linksys_e8450_env
 @@ -0,0 +1,57 @@