pogo_e02: Perform base CONFIG_DM enablement

As these boards support CONFIG_OF_CONTROL today, perform a basic
CONFIG_DM migration.

Cc: Dave Purdy <david.c.purdy@gmail.com>
Signed-off-by: NTom Rini <trini@konsulko.com>

configs/pogo_e02_defconfig

@@ -9,6 +9,7 @@ CONFIG_ENV_SIZE=0x20000
 CONFIG_ENV_OFFSET=0x60000
 CONFIG_DEFAULT_DEVICE_TREE="kirkwood-pogo_e02"
 CONFIG_IDENT_STRING="\nPogo E02"
+# CONFIG_SYS_MALLOC_F is not set
 CONFIG_BOOTDELAY=3
 CONFIG_USE_PREBOOT=y
 # CONFIG_DISPLAY_BOARDINFO is not set
@@ -31,6 +32,7 @@ CONFIG_ENV_OVERWRITE=y
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_NETCONSOLE=y
+CONFIG_DM=y
 # CONFIG_MMC is not set
 CONFIG_MTD=y
 CONFIG_MTD_RAW_NAND=y