spi: spi-geni-qcom: Use DMA mode for SPI responder requester

SPI Transfer mode selection is based on length but in SPI responder case
we get some latency for FIFO mode transfer that will cause some delay
in SPI responder transfer and we get "TX_FIFO_RD_ERR" interrupt. Moving
SPI responder to DMA mode for all transfer will not have this latency
issue and SPI requester/responder  will be in sync and we won't get any
error related to SPI requester/responder sync.

Change-Id: I6b9676aad2a4875a9ff6c4d998a45d2cd8a14cfa
Signed-off-by: Ashish Kori <akori@codeaurora.org>