spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register

In sun6i_spi_transfer_one() the Interrupt Control Register is written three
times. This patch collates the three writes into one.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20200706143443.9855-10-mkl@pengutronix.de


Signed-off-by: Mark Brown <broonie@kernel.org>