feat: introduce SError exception handler

Introduce SError exception handler along with support to register a
custom handler. The default behaviour is same as before if no handler
is registered.
This patch will allow tests to do a graceful exit after handling an
SError.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Idbe37d3690e3a8e08fa3b0dff496d18d3022a8fc
diff --git a/tftf/framework/framework.mk b/tftf/framework/framework.mk
index ddae823..ef59502 100644
--- a/tftf/framework/framework.mk
+++ b/tftf/framework/framework.mk
@@ -82,6 +82,7 @@
 # ARMv8.3 Pointer Authentication support files
 FRAMEWORK_SOURCES	+=						\
 	lib/exceptions/aarch64/sync.c					\
+	lib/exceptions/aarch64/serror.c					\
 	lib/extensions/pauth/aarch64/pauth.c				\
 	lib/extensions/pauth/aarch64/pauth_helpers.S			\
 	lib/extensions/sme/aarch64/sme.c				\