spi: dw-mmio: avoid hardcoded field mask

Define a mask for the IF_SI_OWNER field.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-dw-mmio.c

@@ -36,6 +36,7 @@ struct dw_spi_mmio {
 #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL	0x24
 #define OCELOT_IF_SI_OWNER_OFFSET		4
 #define JAGUAR2_IF_SI_OWNER_OFFSET		6
+#define MSCC_IF_SI_OWNER_MASK			GENMASK(1, 0)
 #define MSCC_IF_SI_OWNER_SISL			0
 #define MSCC_IF_SI_OWNER_SIBM			1
 #define MSCC_IF_SI_OWNER_SIMC			2
@@ -102,7 +103,7 @@ static int dw_spi_mscc_init(struct platform_device *pdev,
 
 	/* Select the owner of the SI interface */
 	regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
-			   0x3 << if_si_owner_offset,
+			   MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
 			   MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
 
 	dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;