mtd: rawnand: brcmnand: Fix sparse warnings in bcma_nand

sparse was unhappy about the way we woulc call cpu_to_be32/be32_to_cpu,
apply the appropriate casting to silence the warnings.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/ZNHPJFYLO64EGI5QUT7HZ63J7O5J2G7N/
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220125225243.15201-1-f.fainelli@gmail.com

drivers/mtd/nand/raw/brcmnand/bcma_nand.c

@@ -58,7 +58,7 @@ static u32 brcmnand_bcma_read_reg(struct brcmnand_soc *soc, u32 offset)
 
 	/* Swap if necessary */
 	if (brcmnand_bcma_needs_swapping(offset))
-		val = be32_to_cpu(val);
+		val = be32_to_cpu((__force __be32)val);
 	return val;
 }
 
@@ -75,7 +75,7 @@ static void brcmnand_bcma_write_reg(struct brcmnand_soc *soc, u32 val,
 
 	/* Swap if necessary */
 	if (brcmnand_bcma_needs_swapping(offset))
-		val = cpu_to_be32(val);
+		val = (__force u32)cpu_to_be32(val);
 
 	bcma_cc_write32(sc->cc, offset, val);
 }