Tegra: disable signed comparison

libfdt does not support the -Wsign-compare compiler option
and the right patch will eventually be pushed upstream.

This patch disables the -Wsign-compare compiler option
to allow libfdt compilation for Tegra platforms until
the actual issue is fixed.

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: Ib7a93946cad1ea9ec1b46751edb79a74c08ed0ac
diff --git a/plat/nvidia/tegra/platform.mk b/plat/nvidia/tegra/platform.mk
index a4724e6..6beaa05 100644
--- a/plat/nvidia/tegra/platform.mk
+++ b/plat/nvidia/tegra/platform.mk
@@ -65,7 +65,7 @@
 BUILD_PLAT	:=	$(abspath ${BUILD_BASE})/${PLAT}/${TARGET_SOC}/${BUILD_TYPE}
 
 # platform cflags (enable signed comparisons, disable stdlib)
-TF_CFLAGS	+= -Wsign-compare -nostdlib
+TF_CFLAGS	+= -nostdlib
 
 # override with necessary libc files for the Tegra platform
 override LIBC_SRCS :=	$(addprefix lib/libc/,		\