spi: qup: Ensure done detection

spi: qup: Ensure done detection

This patch fixes an issue where a SPI transaction has completed, but the
done condition is missed.  This occurs because at the time of interrupt the
MAX_INPUT_DONE_FLAG is not asserted.  However, in the process of reading
blocks of data from the FIFO, the last portion of data comes in.

The opflags read at the beginning of the irq handler no longer matches the
current opflag state.  To get around this condition, the block read
function should update the opflags so that done detection is correct after
the return.

Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>