ti: keystone2: Imply NFS command support

TI KS2 boards have the nfs command in their common environment boot
configuration, enable this command.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ef48864..6d97136 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -792,6 +792,7 @@
 	select SYS_ARCH_TIMER
 	select SYS_THUMB_BUILD
 	imply CMD_MTDPARTS
+	imply CMD_NFS
 	imply CMD_SAVES
 	imply FIT