spi: spi-geni-qcom: Initialize clk params to zero in FIFO mode

Keep the clock params zero initialized during every transfer mode setup
to prevent using the previous transactions clock configurations.

Change-Id: Ibe5c21516872696499af73931c83397c2745de0f
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>