ARM: imx6: Add UART2 for low-level debug

To be able to enable early debugging on boards using the UART2 for the
console, add the option for early debugging on UART2.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 85348a0..0f876c2 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -180,6 +180,14 @@
 		  Say Y here if you want kernel low-level debugging support
 		  on i.MX50 or i.MX53.
 
+	config DEBUG_IMX6Q_UART2
+		bool "i.MX6Q Debug UART2"
+		depends on SOC_IMX6Q
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on i.MX6Q UART2. This is correct for e.g. the SabreLite
+                  board.
+
 	config DEBUG_IMX6Q_UART4
 		bool "i.MX6Q Debug UART4"
 		depends on SOC_IMX6Q