spi: Return true/false (not 1/0) from bool function

spi: Return true/false (not 1/0) from bool function

Return boolean values ("true" or "false") instead of 1 or 0 from bool
function.

As reported by coccicheck:
./drivers/spi/spi-s3c64xx.c:385:9-10: WARNING: return of 0/1 in function
's3c64xx_spi_can_dma' with return type bool

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220609071250.59509-1-yang.lee@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>