drivers: convert makefiles to Kbuild style

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/drivers/input/Makefile b/drivers/input/Makefile
index 7885403..a8e9be2 100644
--- a/drivers/input/Makefile
+++ b/drivers/input/Makefile
@@ -5,34 +5,12 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-include $(TOPDIR)/config.mk
-
-LIB	:= $(obj)libinput.o
-
-COBJS-$(CONFIG_I8042_KBD) += i8042.o
-COBJS-$(CONFIG_TEGRA_KEYBOARD) += tegra-kbc.o
-COBJS-$(CONFIG_CROS_EC_KEYB) += cros_ec_keyb.o
+obj-$(CONFIG_I8042_KBD) += i8042.o
+obj-$(CONFIG_TEGRA_KEYBOARD) += tegra-kbc.o
+obj-$(CONFIG_CROS_EC_KEYB) += cros_ec_keyb.o
 ifdef CONFIG_PS2KBD
-COBJS-y += keyboard.o pc_keyb.o
-COBJS-$(CONFIG_PS2MULT) += ps2mult.o ps2ser.o
+obj-y += keyboard.o pc_keyb.o
+obj-$(CONFIG_PS2MULT) += ps2mult.o ps2ser.o
 endif
-COBJS-y += input.o
-COBJS-$(CONFIG_OF_CONTROL) += key_matrix.o
-
-COBJS	:= $(COBJS-y)
-SRCS	:= $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-
-all:	$(LIB)
-
-$(LIB):	$(obj).depend $(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
+obj-y += input.o
+obj-$(CONFIG_OF_CONTROL) += key_matrix.o