Convert CONFIG_PCIE_IMX to Kconfig

This converts the following to Kconfig:
   CONFIG_PCIE_IMX

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/gwventana_emmc_defconfig b/configs/gwventana_emmc_defconfig
index 0044d89..ea9e7e2 100644
--- a/configs/gwventana_emmc_defconfig
+++ b/configs/gwventana_emmc_defconfig
@@ -114,6 +114,7 @@
 CONFIG_FEC_MXC=y
 CONFIG_MII=y
 CONFIG_PCI=y
+CONFIG_PCIE_IMX=y
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y
 CONFIG_POWER_LEGACY=y