da850: modifications for Logic PD Rev.3 AM18xx EVM

AHCLKR/UART1_RTS/GP0[11] pin needs to be configured for
NOR to work on Rev.3 EVM. When GP0[11] is low,
the SD0 interface will not work, but NOR flash will.

Signed-off-by: Rajashekhara, Sudhakar <sudhakar.raj@ti.com>
Signed-off-by: Nagabhushana Netagunte <nagabhushana.netagunte@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>