Spi driver configuration
------------------------
Following PCDs are available for configuration of spi driver:

 gMarvellTokenSpaceGuid.PcdSpiClockFrequency

Frequency (in Hz) of SPI clock

 gMarvellTokenSpaceGuid.PcdSpiMaxFrequency

Max SCLK line frequency (in Hz) (max transfer frequency)

 gMarvellTokenSpaceGuid.PcdSpiDefaultMode

default SCLK mode (see SPI_MODE enum in file
Platform/Marvell/Drivers/Spi/MvSpi.h)