SiP: Don't validate entrypoint if state switch is impossible

Switching execution states is only possible if EL3 is AArch64.
As such there is no need to validate the entrypoint on AArch32 builds.

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
Change-Id: I3c1eb25b5df296a492870641d274bf65213c6608
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index acc3797..ccb851e 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -215,13 +215,15 @@
 BL31_SOURCES		+=	plat/arm/common/arm_bl31_setup.c		\
 				plat/arm/common/arm_pm.c			\
 				plat/arm/common/arm_topology.c			\
-				plat/arm/common/execution_state_switch.c	\
 				plat/common/plat_psci_common.c
 
 ifeq (${ENABLE_PMF}, 1)
-BL31_SOURCES		+=	plat/arm/common/arm_sip_svc.c			\
+ifeq (${ARCH}, aarch64)
+BL31_SOURCES		+=	plat/arm/common/aarch64/execution_state_switch.c\
+				plat/arm/common/arm_sip_svc.c			\
 				lib/pmf/pmf_smc.c
 endif
+endif
 
 ifeq (${EL3_EXCEPTION_HANDLING},1)
 BL31_SOURCES		+=	plat/arm/common/aarch64/arm_ehf.c