i.MX27 family: Add the Phytec PCM970 evaluation board

The Phytec phyCORE-i.MX27 CPU module is delivered with the PCM970
baseboard by default. This patch adds support for the hardware.

This code is only an empty stub; it is filled up with functionality
in a later patch series.

Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>

diff --git a/arch/arm/mach-mx2/Kconfig b/arch/arm/mach-mx2/Kconfig
index 4c19e1c..1eaa97c 100644
--- a/arch/arm/mach-mx2/Kconfig
+++ b/arch/arm/mach-mx2/Kconfig
@@ -23,3 +23,17 @@
 	help
 	  Include support for phyCORE-i.MX27 (aka pcm038) platform. This
 	  includes specific configurations for the module and its peripherals.
+
+choice
+	prompt "Baseboard"
+	depends on MACH_PCM038
+	default MACH_PCM970_BASEBOARD
+
+config MACH_PCM970_BASEBOARD
+	prompt "PHYTEC PCM970 development board"
+	bool
+	help
+	  This adds board specific devices that can be found on Phytec's
+	  PCM970 evaluation board.
+
+endchoice