stm32mp1: board: remove board_check_usb_power when ADC is not activated

Avoid compilation issue when CONFIG_ADC is not activated

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index 1f6ee3f..12974a6 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -297,6 +297,7 @@
 		hang();
 }
 
+#ifdef CONFIG_ADC
 static int board_check_usb_power(void)
 {
 	struct ofnode_phandle_args adc_args;
@@ -430,6 +431,7 @@
 
 	return 0;
 }
+#endif /* CONFIG_ADC */
 
 static void sysconf_init(void)
 {
@@ -660,8 +662,10 @@
 	}
 #endif
 
+#ifdef CONFIG_ADC
 	/* for DK1/DK2 boards */
 	board_check_usb_power();
+#endif /* CONFIG_ADC */
 
 	/* Check the boot-source to disable bootdelay */
 	boot_device = env_get("boot_device");