Sync tf_config files with internal CI

Signed-off-by: Zelalem <zelalem.aweke@arm.com>
Change-Id: I064f4f252fe7d3770719dee040feb96ea180a9bb
diff --git a/tf_config/rpi3-stack-protector b/tf_config/rpi3-stack-protector
new file mode 100644
index 0000000..d5d417c
--- /dev/null
+++ b/tf_config/rpi3-stack-protector
@@ -0,0 +1,4 @@
+CROSS_COMPILE=aarch64-none-elf-
+PLAT=rpi3
+PRELOADED_BL33_BASE=0xDEADBEEF
+ENABLE_STACK_PROTECTOR=strong