uboot-imx

tx25: fix crash while booting Linux

Currently booting Linux on TX25 board doesn't work
since there is no correct mach-id and boot parameters
setup for tx25 board. Fix it now.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: John Rigby <jcrigby@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>