feat(rng_trap): add tests for FEAT_RNG_TRAP

Added 2 tests that expect a trap to be triggered when a read is
performed on:
1. RNDR register
2. RNDRRS register
The result will be a panic signal and the whole system will halt,
as there is no handler set for such trap.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: Ia979e60a106b394cc09dfdf94115354fb72142d1
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index b366cdd..e10ddab 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -417,6 +417,10 @@
 DEFINE_SYSREG_RW_FUNCS(pmevtyper0_el0)
 DEFINE_SYSREG_READ_FUNC(pmevcntr0_el0)
 
+/* Armv8.5 FEAT_RNG Registers */
+DEFINE_SYSREG_READ_FUNC(rndr)
+DEFINE_SYSREG_READ_FUNC(rndrrs)
+
 /* GICv3 System Registers */
 
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_sre_el1, ICC_SRE_EL1)