spi: zynq_qspi: Add a check for baudrate and set default if not in limits

spi: zynq_qspi: Add a check for baudrate and set default if not in limits

Add a check afer baudrate calculation to see if the resultant value
falls within the range, else set it to default baudrate value.

Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Link: https://lore.kernel.org/r/20220131052240.23403-4-ashok.reddy.soma@xilinx.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>