boards: st: stm32h747i_disco: add SD disk name

Add a disk name to the SDMMC node, as done for all other SD card
compatibles in tree.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

boards/st/stm32h747i_disco/stm32h747i_disco_stm32h747xx_m7.dts

@@ -239,6 +239,7 @@ zephyr_udc0: &usbotg_hs {
 			&sdmmc1_ck_pc12 &sdmmc1_cmd_pd2>;
 	pinctrl-names = "default";
 	cd-gpios = <&gpioi 8 GPIO_ACTIVE_LOW>;
+	disk-name = "SD";
 };
 
 &quadspi {