ANDROID: db845c: Enable device tree overlay support

This DTC_FLAGS will build the base platform dtbs with
overlay support. Otherwise fdtoverlay command throws
"FDT_ERR_NOTFOUND" error at the build time.

Missing/broken DTBO partition support on DB845c and RB5 is
the primary reason we have to apply DTB overlays at the
build time.

This patch will help enable currently out-of-tree/WIP (GKI)
features on supported devboards, and help us start testing
them in the LKFT builds.

Bug: 146449535
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: Ie1510d93532544683a1408e88473da5a83fc3a60
diff --git a/build.config.db845c b/build.config.db845c
index 6bbb310..c442d66 100644
--- a/build.config.db845c
+++ b/build.config.db845c
@@ -7,6 +7,8 @@
 PRE_DEFCONFIG_CMDS="KCONFIG_CONFIG=${ROOT_DIR}/${KERNEL_DIR}/arch/arm64/configs/${DEFCONFIG} ${ROOT_DIR}/${KERNEL_DIR}/scripts/kconfig/merge_config.sh -m -r ${ROOT_DIR}/${KERNEL_DIR}/arch/arm64/configs/gki_defconfig ${ROOT_DIR}/${FRAGMENT_CONFIG}"
 POST_DEFCONFIG_CMDS="rm ${ROOT_DIR}/${KERNEL_DIR}/arch/arm64/configs/${DEFCONFIG}"
 
+DTC_FLAGS="${DTC_FLAGS} -@"
+
 MAKE_GOALS="${MAKE_GOALS}
 qcom/sdm845-db845c.dtb
 qcom/qrb5165-rb5.dtb