mxs: enable nvmem support

fixes build error due to missing kernel config options

Signed-off-by: Felix Fietkau <[email protected]>

target/linux/mxs/config-4.4

@@ -212,6 +212,8 @@ CONFIG_NEED_PER_CPU_KM=y
 CONFIG_NET_PTP_CLASSIFY=y
 CONFIG_NLS=y
 CONFIG_NO_BOOTMEM=y
+CONFIG_NVMEM=y
+CONFIG_NVMEM_MXS_OCOTP=y
 CONFIG_OF=y
 CONFIG_OF_ADDRESS=y
 CONFIG_OF_EARLY_FLATTREE=y