spi: spi-msm-geni: Add support to disable dma mode for SPI transfers

QUPv3 controller supports different modes of data transfers for SPI.
Add support to choose only fifo mode for data transfers. Currently
SSC DMA path is broken as agnoc is not enabled. This clk is owned by
SLPI, once SLPI change is mainlined we can use DMA mode for SSC QUP
also.

Change-Id: Ie4c67be29adba9d6c5a5bb1b9eb2161a2b384100
Signed-off-by: Ashish Kori <akori@codeaurora.org>