staging: spi: mt7621: Remove superfluous SPI_BPW_MASK definition

This patch removes the SPI_BPW_MASK definition as this is already
available in include/linux/spi/spi.h.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: Sankalp Negi <sankalpnegi2310@gmail.com>
Cc: Chuanhong Guo <gch981213@gmail.com>
Cc: John Crispin <john@phrozen.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-spi/spi-mt7621.c

@@ -19,8 +19,6 @@
 #include <linux/reset.h>
 #include <linux/spi/spi.h>
 
-#define SPI_BPW_MASK(bits) BIT((bits) - 1)
-
 #define DRIVER_NAME			"spi-mt7621"
 /* in usec */
 #define RALINK_SPI_WAIT_MAX_LOOP	2000