am335x: Enable MMC1 clock

We must not assume ROM has enabled the clock for MMC1.

Reported-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Tom Rini <trini@ti.com>
am335x_evm: enable gpio command
am335x_evm: HACK to turn on BeagleBone LEDs

* This might break non-BeagleBone platforms