board/ti/dra7xx: add support for parallel NOR

board/ti/dra7xx: add support for parallel NOR

This patch adds support for parallel NOR device (S29GL512S10) present on J6-EVM.
The Flash device is connected to GPMC controller on chip-select[0] and accessed
as memory-mapped device. It has data-witdh=x16, capacity-64MBytes(512Mbits) and
is CFI compatible.

As multiple devices are share GPMC pins on this board, so following board
settings are required to detect NOR device:
     SW5.1 (NAND_BOOTn) = OFF (logic-1)
     SW5.2 (NOR_BOOTn)  = ON  (logic-0) /* Active-low */
     SW5.3 (eMMC_BOOTn) = OFF (logic-1)
     SW5.4 (QSPI_BOOTn) = OFF (logic-1)

And also set appropriate SYSBOOT configurations:
     SW3.1 (SYSBOOT[ 8])= ON  (logic-1) /* selects SYS_CLK1 speed */
     SW3.2 (SYSBOOT[ 9])= OFF (logic-0) /* selects SYS_CLK1 speed */
     SW3.3 (SYSBOOT[10])= ON  (logic-1) /* wait-pin monitoring = enabled */
     SW3.4 (SYSBOOT[11])= OFF (logic-0) /* device type: Non Muxed */
     SW3.5 (SYSBOOT[12])= OFF (logic-0) /* device type: Non Muxed */
     SW3.6 (SYSBOOT[13])= ON  (logic-1) /* device bus-width: 1(x16) */
     SW3.7 (SYSBOOT[14])= OFF (logic-0) /* reserved */
     SW3.8 (SYSBOOT[15])= ON  (logic-1) /* reserved */

Also, following changes are required to enable NOR Flash support in
dra7xx_evm board profile: