spi: spi-geni-qcom: Fix the chip select setup parameters

The demux select register requires the CS to be specificed as a value not
a bit position.
Also the parameters for the M_CMD register are bit positions and not actual
values. Modify the parameter enums for SPI to reflect this.

Change-Id: I2afe27723f10edf911ed741c914df4440ff0359f
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>