board: phytec: Add common PHYTEC SoM detection

Recent shipped PHYTEC SoMs come with an i2c  EEPROM containing
information about the hardware such as board revision and variant.
This can be used for RAM detection and loading device tree overlays
during kernel start.

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>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/board/phytec/common/Kconfig b/board/phytec/common/Kconfig
new file mode 100644
index 0000000..d614d45
--- /dev/null
+++ b/board/phytec/common/Kconfig
@@ -0,0 +1,5 @@
+config PHYTEC_SOM_DETECTION
+	bool "Support SoM detection for PHYTEC platforms"
+	select SPL_CRC8 if SPL
+	help
+	   Support of I2C EEPROM based SoM detection.