drivers: convert makefiles to Kbuild style

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/drivers/bios_emulator/Makefile b/drivers/bios_emulator/Makefile
index d94a144..dd42e0f 100644
--- a/drivers/bios_emulator/Makefile
+++ b/drivers/bios_emulator/Makefile
@@ -1,12 +1,8 @@
-include $(TOPDIR)/config.mk
-
-LIB := $(obj)libatibiosemu.o
-
 X86DIR  = x86emu
 
 $(shell mkdir -p $(obj)$(X86DIR))
 
-COBJS-$(CONFIG_BIOSEMU)	= atibios.o biosemu.o besys.o bios.o \
+obj-$(CONFIG_BIOSEMU)	= atibios.o biosemu.o besys.o bios.o \
 	$(X86DIR)/decode.o \
 	$(X86DIR)/ops2.o \
 	$(X86DIR)/ops.o \
@@ -14,26 +10,9 @@
 	$(X86DIR)/sys.o \
 	$(X86DIR)/debug.o
 
-COBJS	:= $(COBJS-y)
-SRCS	:= $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-
 EXTRA_CFLAGS += -I. -I./include -I$(TOPDIR)/include \
 	-D__PPC__  -D__BIG_ENDIAN__
 
 CFLAGS += $(EXTRA_CFLAGS)
 HOSTCFLAGS += $(EXTRA_CFLAGS)
 CPPFLAGS += $(EXTRA_CFLAGS)
-
-all:	$(LIB)
-
-$(LIB): $(obj).depend $(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################