mtd: rawnand: Remove nand_do_read() prototype from rawnand.h

nand_do_read() is a static function implemented in nand_base.c. There's
no good reason to expose its prototype in rawnand.h.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

include/linux/mtd/rawnand.h

@@ -1545,8 +1545,6 @@ int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs);
 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt);
 int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
 		    int allowbbt);
-int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len,
-		 size_t *retlen, uint8_t *buf);
 
 /**
  * struct platform_nand_chip - chip level device structure