mtd: rawnand: omap_elm: Fix incorrect type in assignment

Once the ECC word endianness is converted to BE32, we force cast it
to u32 so we can use elm_write_reg() which in turn uses writel().

Fixes below sparse warnings:

   drivers/mtd/nand/raw/omap_elm.c:180:37: sparse:     expected unsigned int [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:180:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:185:37: sparse:     expected unsigned int [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:185:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:190:37: sparse:     expected unsigned int [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:190:37: sparse:     got restricted __be32 [usertype]
>> drivers/mtd/nand/raw/omap_elm.c:200:40: sparse: sparse: restricted __be32 degrades to integer
   drivers/mtd/nand/raw/omap_elm.c:206:39: sparse: sparse: restricted __be32 degrades to integer
   drivers/mtd/nand/raw/omap_elm.c:210:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:210:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:213:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:213:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:216:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:216:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:219:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:219:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:222:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:222:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:225:37: sparse:     expected unsigned int [assigned] [usertype] val
   drivers/mtd/nand/raw/omap_elm.c:225:37: sparse:     got restricted __be32 [usertype]
   drivers/mtd/nand/raw/omap_elm.c:228:39: sparse: sparse: restricted __be32 degrades to integer

Fixes: bf224335 ("mtd: devices: elm: Add support for ELM error correction")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306212211.WDXokuWh-lkp@intel.com/


Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230624184021.7740-1-rogerq@kernel.org