tests: fs: update overlay files for RA8x1 devices

Add interrupts information for these boards:
- ek_ra8m1
- ek_ra8d1

Signed-off-by: The Nguyen <the.nguyen.yf@renesas.com>

Author: thenguyenyf

tests/subsys/fs/ext2/boards/ek_ra8d1.overlay

@@ -4,6 +4,10 @@
  */
 
 &sdhc1 {
+	interrupt-names = "accs", "card", "dma-req";
+	interrupts = <94 12>, <95 12>, <96 12>;
+	status = "okay";
+
 	sdmmc {
 		partition {
 			compatible = "fixed-partitions";

tests/subsys/fs/ext2/boards/ek_ra8m1.overlay

@@ -4,6 +4,10 @@
  */
 
 &sdhc0 {
+	interrupt-names = "accs", "card", "dma-req";
+	interrupts = <94 12>, <95 12>, <96 12>;
+	status = "okay";
+
 	sdmmc {
 		partition {
 			compatible = "fixed-partitions";