powerpc/p1022ds: add support for SPI and SD boot

powerpc/p1022ds: add support for SPI and SD boot

Add TLB mappings, board target options, and configuration items
need for SPI/SD boot.

Since P1022DS RevB board, the NOR flash have been changed to 16 bit/28bit
address flash, therefore, when SDHC/ESPI booting and access to eLBC,
the PMUXCR[0~1] must be set to 10b, and PMUXCR[9~10] must be set to
00b for them.

Configure the PX_BRDCFG0[0~1] to 10b which is connected to
SPI devices as SPI_CS(0:3)_B.

Signed-off-by: Matthew McClintock <[email protected]>
Signed-off-by: Jerry Huang <[email protected]>
Signed-off-by: Jiang Yutang <[email protected]>
Signed-off-by: Andy Fleming <[email protected]>