Do not reset GPIO0 at  boot-up because GPIO0 is used
on AM335x EVM-SK to control VTT regulators on DDR3.

Without this EVM-SK boards fail to boot-up because
of DDR3 corruption.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Benoit Cousson <bcousson@baylibre.com>