refactor(aarch64): rename do_panic and el3_panic

Current panic call invokes do_panic which calls el3_panic, but now panic
handles only panic from EL3 anid clear separation to use lower_el_panic()
which handles panic from lower ELs.

So now we can remove do_panic and just call el3_panic for all panics.

Change-Id: I739c69271b9fb15c1176050877a9b0c0394dc739
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/plat/renesas/common/aarch64/plat_helpers.S b/plat/renesas/common/aarch64/plat_helpers.S
index 21c3bed..a7fdfa0 100644
--- a/plat/renesas/common/aarch64/plat_helpers.S
+++ b/plat/renesas/common/aarch64/plat_helpers.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, Arm Limited and Contributors. All rights reserved.
  * Copyright (c) 2015-2021, Renesas Electronics Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
@@ -126,7 +126,7 @@
 exit:
 	ret	x9
 _panic:
-	b	do_panic
+	b	el3_panic
 #endif
 
 endfunc plat_get_my_entrypoint