platform/surface: aggregator: Use y instead of objs in Makefile

obj-$(CONFIG_SURFACE_AGGREGATOR) += surface_aggregator.o

surface_aggregator-objs := core.o

surface_aggregator-objs += ssh_parser.o

surface_aggregator-objs += ssh_packet_layer.o

surface_aggregator-objs += ssh_request_layer.o

surface_aggregator-objs += controller.o

ifeq ($(CONFIG_SURFACE_AGGREGATOR_BUS),y)

surface_aggregator-objs += bus.o

endif

surface_aggregator-y := core.o

surface_aggregator-y += ssh_parser.o

surface_aggregator-y += ssh_packet_layer.o

surface_aggregator-y += ssh_request_layer.o

surface_aggregator-$(CONFIG_SURFACE_AGGREGATOR_BUS) += bus.o

surface_aggregator-y += controller.o