spi: mchp-pci1xxxx: Fix minor bugs in spi-pci1xxxx

Merge series from Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>:

This patch series fixes the following bugs in spi-pci1xxxx driver:
1. Length of SPI transactions is improper
2. SPI transactions fail after suspend and resume
3. Incorrect implementation of pci1xxxx_spi_set_cs API