mx6: use CONFIG_MX6 instead of CONFIG_MX6Q

Use CONFIG_MX6 when the particular processor
variant isn't important.

Reserve the use of CONFIG_MX6Q to
specifically test for quad cores variant.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
diff --git a/drivers/gpio/mxc_gpio.c b/drivers/gpio/mxc_gpio.c
index 2c79bff..a388064 100644
--- a/drivers/gpio/mxc_gpio.c
+++ b/drivers/gpio/mxc_gpio.c
@@ -42,14 +42,14 @@
 	[1] = GPIO2_BASE_ADDR,
 	[2] = GPIO3_BASE_ADDR,
 #if defined(CONFIG_MX25) || defined(CONFIG_MX27) || defined(CONFIG_MX51) || \
-		defined(CONFIG_MX53) || defined(CONFIG_MX6Q)
+		defined(CONFIG_MX53) || defined(CONFIG_MX6)
 	[3] = GPIO4_BASE_ADDR,
 #endif
-#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6Q)
+#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
 	[4] = GPIO5_BASE_ADDR,
 	[5] = GPIO6_BASE_ADDR,
 #endif
-#if defined(CONFIG_MX53) || defined(CONFIG_MX6Q)
+#if defined(CONFIG_MX53) || defined(CONFIG_MX6)
 	[6] = GPIO7_BASE_ADDR,
 #endif
 };