driver: cache-v5l2: Fix type casting warning on RV32

This patch fixes following warning for the riscv32 toolchain.

drivers/cache/cache-v5l2.c:122:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  122 |         regs = (struct l2cache *)dev_read_addr(dev);
      |                ^

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/drivers/cache/cache-v5l2.c b/drivers/cache/cache-v5l2.c
index c6d3a8f..eda07d3 100644
--- a/drivers/cache/cache-v5l2.c
+++ b/drivers/cache/cache-v5l2.c
@@ -119,7 +119,7 @@
 	struct v5l2_plat *plat = dev_get_plat(dev);
 	struct l2cache *regs;
 
-	regs = (struct l2cache *)dev_read_addr(dev);
+	regs = (struct l2cache *)(uintptr_t)dev_read_addr(dev);
 	plat->regs = regs;
 
 	plat->iprefetch = -EINVAL;