Add CPU specific crash reporting handlers

This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.

Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab
diff --git a/lib/cpus/aarch64/aem_generic.S b/lib/cpus/aarch64/aem_generic.S
index 19c9433..58a64a6 100644
--- a/lib/cpus/aarch64/aem_generic.S
+++ b/lib/cpus/aarch64/aem_generic.S
@@ -68,6 +68,19 @@
 	mov	x0, #DCCISW
 	b	dcsw_op_all
 
+	/* ---------------------------------------------
+	 * This function provides cpu specific
+	 * register information for crash reporting.
+	 * It needs to return with x6 pointing to
+	 * a list of register names in ascii and
+	 * x8 - x15 having values of registers to be
+	 * reported.
+	 * ---------------------------------------------
+	 */
+func aem_generic_cpu_reg_dump
+	mov	x6, #0 /* no registers to report */
+	ret
+
 
 /* cpu_ops for Base AEM FVP */
 declare_cpu_ops aem_generic, BASE_AEM_MIDR, 1