eNET: Fix undefined reference to `monitor_flash_len'

commit cfbe861506e2dc3250ac99dc45bb3d1ac60f4857 removed the definition of
monitor_flash_len from the eNET which was not picked up due to extensive
use of the SRAM configuration target for testing

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
1 file changed