plat/qemu_sbsa: Remove cortex_a53 and aem_generic

The qemu_sbsa platform uses 42bit address size but
the cortex-a53 only supports 40bit addressing, the
cpu is incompatible with the platform.

The aem_generic is also not used with qemu_sbsa, in
fact, the platform currently only properly supports
the cortex-a57 cpu.

Change-Id: I91c92533116f1c3451d01ca99824e91d3d58df14
Signed-off-by: Tomas Pilar <tomas@nuviateam.com>

plat/qemu/qemu_sbsa/platform.mk

@@ -47,9 +47,7 @@ BL1_SOURCES		+=	drivers/io/io_semihosting.c			\
 				${PLAT_QEMU_COMMON_PATH}/${ARCH}/plat_helpers.S	\
 				${PLAT_QEMU_COMMON_PATH}/qemu_bl1_setup.c
 
-BL1_SOURCES		+=	lib/cpus/aarch64/aem_generic.S			\
-				lib/cpus/aarch64/cortex_a53.S			\
-				lib/cpus/aarch64/cortex_a57.S
+BL1_SOURCES		+=	lib/cpus/aarch64/cortex_a57.S
 
 BL2_SOURCES		+=	drivers/io/io_semihosting.c			\
 				drivers/io/io_storage.c				\
@@ -75,9 +73,7 @@ QEMU_GIC_SOURCES	:=	${GICV3_SOURCES}				\
 				plat/common/plat_gicv3.c			\
 				${PLAT_QEMU_COMMON_PATH}/qemu_gicv3.c
 
-BL31_SOURCES		+=	lib/cpus/aarch64/aem_generic.S			\
-				lib/cpus/aarch64/cortex_a53.S			\
-				lib/cpus/aarch64/cortex_a57.S			\
+BL31_SOURCES		+=	lib/cpus/aarch64/cortex_a57.S			\
 				lib/semihosting/semihosting.c			\
 				lib/semihosting/${ARCH}/semihosting_call.S	\
 				plat/common/plat_psci_common.c			\