mtd: rawnand: sunxi: Convert to common field_{get,prep}() helpers

Drop the driver-specific field_get() and field_prep() macros, in favor
of the globally available variants from <linux/bitfield.h>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: geertu

drivers/mtd/nand/raw/sunxi_nand.c

@@ -29,12 +29,6 @@
 #include <linux/iopoll.h>
 #include <linux/reset.h>
 
-/* non compile-time field get/prep */
-#undef field_get
-#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1))
-#undef field_prep
-#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask))
-
 #define NFC_REG_CTL		0x0000
 #define NFC_REG_ST		0x0004
 #define NFC_REG_INT		0x0008