Make setjmp.h prototypes comply with the C standard

Instead of having a custom implementation of setjmp() and longjmp() it
is better to follow the C standard.

The comments in setjmp.h are no longer needed as there are no deviations
from the expected one, so they have been removed.

All SDEI code that relied on them has been fixed to use the new function
prototypes and structs.

Change-Id: I6cd2e21cb5a5bcf81ba12283f2e4c067bd5172ca
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/services/std_svc/sdei/sdei_private.h b/services/std_svc/sdei/sdei_private.h
index 1486431..8cc66e7 100644
--- a/services/std_svc/sdei/sdei_private.h
+++ b/services/std_svc/sdei/sdei_private.h
@@ -243,6 +243,6 @@
 int sdei_intr_handler(uint32_t intr_raw, uint32_t flags, void *handle,
 		void *cookie);
 bool can_sdei_state_trans(sdei_entry_t *se, sdei_action_t act);
-void begin_sdei_synchronous_dispatch(struct jmpbuf *buffer);
+void begin_sdei_synchronous_dispatch(jmp_buf *buffer);
 
 #endif /* SDEI_PRIVATE_H */