mtd: rawnand: Use unsigned types for nand_chip unsigned values

page_shift, phys_erase_shift, bbt_erase_shift, chip_shift, pagemask,
subpagesize and badblockbits are all positive values, so declare
them as unsigned.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200529111322.7184-2-miquel.raynal@bootlin.com

include/linux/mtd/rawnand.h

@@ -1110,11 +1110,11 @@ struct nand_chip {
 	unsigned int options;
 	unsigned int bbt_options;
 
-	int page_shift;
-	int phys_erase_shift;
-	int bbt_erase_shift;
-	int chip_shift;
-	int pagemask;
+	unsigned int page_shift;
+	unsigned int phys_erase_shift;
+	unsigned int bbt_erase_shift;
+	unsigned int chip_shift;
+	unsigned int pagemask;
 	u8 *data_buf;
 
 	struct {
@@ -1122,10 +1122,10 @@ struct nand_chip {
 		int page;
 	} pagecache;
 
-	int subpagesize;
+	unsigned int subpagesize;
 	int onfi_timing_mode_default;
 	unsigned int badblockpos;
-	int badblockbits;
+	unsigned int badblockbits;
 
 	struct nand_id id;
 	struct nand_parameters parameters;