mt7621: enable CONFIG_MTD_UBI_NVMEM, CONFIG_NVMEM_LAYOUT_U_BOOT_ENV

Enable above drivers for mt7621 targets. They are needed for retrieving a MAC
address stored in a U-boot environment residing on an UBI volume.

Signed-off-by: Mauri Sandberg <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/16573
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/ramips/mt7621/config-6.6

@@ -176,6 +176,7 @@ CONFIG_MTD_SPLIT_UIMAGE_FW=y
 CONFIG_MTD_UBI=y
 CONFIG_MTD_UBI_BEB_LIMIT=20
 CONFIG_MTD_UBI_BLOCK=y
+CONFIG_MTD_UBI_NVMEM=y
 CONFIG_MTD_UBI_WL_THRESHOLD=4096
 CONFIG_MTD_VIRT_CONCAT=y
 CONFIG_NEED_DMA_MAP_STATE=y
@@ -201,6 +202,7 @@ CONFIG_NR_CPUS=4
 CONFIG_NVMEM=y
 CONFIG_NVMEM_LAYOUTS=y
 # CONFIG_NVMEM_LAYOUT_MIKROTIK is not set
+CONFIG_NVMEM_LAYOUT_U_BOOT_ENV=y
 CONFIG_OF=y
 CONFIG_OF_ADDRESS=y
 CONFIG_OF_EARLY_FLATTREE=y
@@ -243,7 +245,6 @@ CONFIG_QCOM_NET_PHYLIB=y
 CONFIG_QUEUED_RWLOCKS=y
 CONFIG_QUEUED_SPINLOCKS=y
 CONFIG_RALINK=y
-# CONFIG_RALINK_GDMA is not set
 # CONFIG_RALINK_WDT is not set
 CONFIG_RANDSTRUCT_NONE=y
 CONFIG_RATIONAL=y