fix: add xpaci instruction to exception report

When reporting an exception with ENABLE_PAUTH==1 calling xpaci
before printing the ELR value will remove the PAC and make the
pointer readable.

Change-Id: I45339dbb3396f403768ea3ee780d0c5010da44c4
Signed-off-by: John Powell <john.powell@arm.com>
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index 35d2454..e6b588f 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -231,6 +231,8 @@
 DEFINE_SYSOP_PARAM_FUNC(wfit)
 DEFINE_SYSOP_PARAM_FUNC(wfet)
 
+DEFINE_SYSOP_PARAM_FUNC(xpaci)
+
 DEFINE_RENAME_SYSREG_RW_FUNCS(sys_accdata_el1, SYS_ACCDATA_EL1)
 
 static inline void enable_irq(void)