cache: sifive: Fix -Wint-to-pointer-cast warning

The following warning is seen in cache-sifive-ccache.c in a 32-bit build:

  warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

Fix by casting it with uintptr_t.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/drivers/cache/cache-sifive-ccache.c b/drivers/cache/cache-sifive-ccache.c
index 76c0ab2..c8766f6 100644
--- a/drivers/cache/cache-sifive-ccache.c
+++ b/drivers/cache/cache-sifive-ccache.c
@@ -38,7 +38,7 @@
 {
 	struct sifive_ccache *priv = dev_get_priv(dev);
 
-	info->base = (phys_addr_t)priv->base;
+	info->base = (uintptr_t)priv->base;
 
 	return 0;
 }