mtd: onenand: samsung: Fix pointer cast -Wpointer-to-int-cast warnings on 64 bit

iomem pointers should be casted to unsigned long to avoid
-Wpointer-to-int-cast warnings when compiling on 64-bit platform (e.g.
with COMPILE_TEST):

    drivers/mtd/nand/onenand/samsung_mtd.c: In function ‘s3c_onenand_readw’:
    drivers/mtd/nand/onenand/samsung_mtd.c:251:6: warning:
        cast from pointer to integer of different size [-Wpointer-to-int-cast]
      if ((unsigned int) addr < ONENAND_DATARAM && onenand->bootram_command) {
          ^
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/onenand/samsung_mtd.c

@@ -248,7 +248,7 @@ static unsigned short s3c_onenand_readw(void __iomem *addr)
 	}
 
 	/* BootRAM access control */
-	if ((unsigned int) addr < ONENAND_DATARAM && onenand->bootram_command) {
+	if ((unsigned long)addr < ONENAND_DATARAM && onenand->bootram_command) {
 		if (word_addr == 0)
 			return s3c_read_reg(MANUFACT_ID_OFFSET);
 		if (word_addr == 1)
@@ -289,7 +289,7 @@ static void s3c_onenand_writew(unsigned short value, void __iomem *addr)
 	}
 
 	/* BootRAM access control */
-	if ((unsigned int)addr < ONENAND_DATARAM) {
+	if ((unsigned long)addr < ONENAND_DATARAM) {
 		if (value == ONENAND_CMD_READID) {
 			onenand->bootram_command = 1;
 			return;