[ARM] Kirkwood: Add MPP36 for QNAP TS-11x/TS-21x

MPP36 is used on the QNAP TS-11x/TS-21x devices to indicate how
much RAM there is: it's high for 512 MB RAM (TS-x19) and low for
256 MB (TS-x10).  While this may not be very useful, let's add
it for completeness.

Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
diff --git a/arch/arm/mach-kirkwood/ts219-setup.c b/arch/arm/mach-kirkwood/ts219-setup.c
index ec1a64f..cb0f56d 100644
--- a/arch/arm/mach-kirkwood/ts219-setup.c
+++ b/arch/arm/mach-kirkwood/ts219-setup.c
@@ -152,6 +152,7 @@
 	MPP14_UART1_RXD,	/* PIC controller */
 	MPP15_GPIO,		/* USB Copy button */
 	MPP16_GPIO,		/* Reset button */
+	MPP36_GPIO,		/* RAM: 0: 256 MB, 1: 512 MB */
 	0
 };