spi: s3c64xx: explicitly include <linux/bits.h>

spi: s3c64xx: explicitly include <linux/bits.h>

[ Upstream commit 4568fa574fcef3811a8140702979f076ef0f5bc0 ]

The driver uses GENMASK() but does not include <linux/bits.h>.

It is good practice to directly include all headers used, it avoids
implicit dependencies and spurious breakage if someone rearranges
headers and causes the implicit include to vanish.

Include the missing header.

Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240207120431.2766269-4-tudor.ambarus@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: a3d3eab627bb ("spi: s3c64xx: Use DMA mode from fifo size")
Signed-off-by: Sasha Levin <sashal@kernel.org>