i.MX31 pcm037: Add USB support

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx3/Kconfig b/arch/arm/mach-mx3/Kconfig
index 2829441..2232b7b 100644
--- a/arch/arm/mach-mx3/Kconfig
+++ b/arch/arm/mach-mx3/Kconfig
@@ -34,6 +34,7 @@
 config MACH_PCM037
 	bool "Support Phytec pcm037 (i.MX31) platforms"
 	select ARCH_MX31
+	select MXC_ULPI if USB_ULPI
 	help
 	  Include support for Phytec pcm037 platform. This includes
 	  specific configurations for the board and its peripherals.