feat: test to verify SError reflected back to lower EL from EL3

Tests introduced to verify
  - reflection of errors back to lower EL from EL3 in KFH mode
  - Nested handling of exception in case of FFH mode

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ie9f4b911a65672dcb0dd1673b376872fbe885c24
diff --git a/tftf_config/fvp-ras-ffh-nested b/tftf_config/fvp-ras-ffh-nested
new file mode 100644
index 0000000..34a2d89
--- /dev/null
+++ b/tftf_config/fvp-ras-ffh-nested
@@ -0,0 +1,3 @@
+CROSS_COMPILE=aarch64-none-elf-
+PLAT=fvp
+TESTS=ras-ffh-nested