spi: spi-imx: mx51_ecspi_intctrl(): prefer 'unsigned int' to bare use of 'unsigned'

This patch fixes the following checkpatch warning, by making val an
"unsigned int".

| WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
| +       unsigned val = 0;

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20220502175457.1977983-4-mkl@pengutronix.de


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