kernel: fix linux/spi/spidev.h portability issues with musl

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 45105

target/linux/generic/patches-3.18/214-spidev_h_portability.patch

+--- a/include/uapi/linux/spi/spidev.h
++++ b/include/uapi/linux/spi/spidev.h
+@@ -111,7 +111,7 @@ struct spi_ioc_transfer {
+ 
+ /* not all platforms use <asm-generic/ioctl.h> or _IOC_TYPECHECK() ... */
+ #define SPI_MSGSIZE(N) \
+-	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << _IOC_SIZEBITS)) \
++	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << 13)) \
+ 		? ((N)*(sizeof (struct spi_ioc_transfer))) : 0)
+ #define SPI_IOC_MESSAGE(N) _IOW(SPI_IOC_MAGIC, 0, char[SPI_MSGSIZE(N)])
+ 

target/linux/generic/patches-4.0/214-spidev_h_portability.patch

+--- a/include/uapi/linux/spi/spidev.h
++++ b/include/uapi/linux/spi/spidev.h
+@@ -111,7 +111,7 @@ struct spi_ioc_transfer {
+ 
+ /* not all platforms use <asm-generic/ioctl.h> or _IOC_TYPECHECK() ... */
+ #define SPI_MSGSIZE(N) \
+-	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << _IOC_SIZEBITS)) \
++	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << 13)) \
+ 		? ((N)*(sizeof (struct spi_ioc_transfer))) : 0)
+ #define SPI_IOC_MESSAGE(N) _IOW(SPI_IOC_MAGIC, 0, char[SPI_MSGSIZE(N)])
+