spi: spi-msm-geni: Clear the RX fifo if FIFO has data after timeout

Propagate a change from 4.19 to 5.4 for SPI. 'commit 556e7c13ceaa
("spi: spi-msm-geni: Clear the RX fifo if FIFO has data after timeout")'.

Change-Id: Ica785f7b3cd3a9f9df6d173413ce136c2a018312
Signed-off-by: Vipin Deep Kaur <vkaur@codeaurora.org>