spi:fsl-quadspi support bank register read write

spi:fsl-quadspi support bank register read write

To support bigger than 16MB size qspi flashes, spi framework uses bank
switch to access higher bank or lower bank.

In this patch, QSPI_CMD_BRRD, QSPI_CMD_BRWR, QSPI_CMD_WREAR, QSPI_CMD_RDEAR
is initialized in LUT register with related pad and length configuration.
qspi_op_pp is originally for page programming, this patch reuses this function
for bank register switch and renamed it with qspi_op_write.

Since bank or EAR register is only 1 byte length, however original qspi_op_pp
or now renamed qspi_op_write only support 4 bytes lenght as the access unit,
this will trigger data abort exception when access EAR or bank register.
This is because upper framework passes a 1 bytes pointer to qspi_op_write,
however qspi_op_write treat it as an int pointer. This patch fixes this for
accessing EAR or bank register.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>