board: phytec: common: phytec_som_detection: Add helper for PCB revision

Add helper function to read out the PCB revision of a PHYTEC SoM.

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Reviewed-by: Yannic Moog <y.moog@phytec.de>
Tested-by: Yannic Moog <y.moog@phytec.de>
diff --git a/board/phytec/common/phytec_som_detection.c b/board/phytec/common/phytec_som_detection.c
index 366bdd4..5556273 100644
--- a/board/phytec/common/phytec_som_detection.c
+++ b/board/phytec/common/phytec_som_detection.c
@@ -186,3 +186,18 @@
 
 	return opt;
 }
+
+u8 __maybe_unused phytec_get_rev(struct phytec_eeprom_data *data)
+{
+	struct phytec_api2_data *api2;
+
+	if (!data)
+		data = &eeprom_data;
+
+	if (data->api_rev < PHYTEC_API_REV2)
+		return PHYTEC_EEPROM_INVAL;
+
+	api2 = &data->data.data_api2;
+
+	return api2->pcb_rev;
+}