Makefile: convert makefiles to Kbuild style and delete grep switch

We have converted all makefiles needed to build $(LIBS).

Until this commit we used to grep switch so that U-Boot style
and Kbuild style makefiles coexist.
But we do not need any more.

Goint forward, use always Kbuild style Makefile when adding
a new Makefile

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/board/compal/paz00/Makefile b/board/compal/paz00/Makefile
index fa5c510..824cd2e 100644
--- a/board/compal/paz00/Makefile
+++ b/board/compal/paz00/Makefile
@@ -14,28 +14,8 @@
 # more details.
 #
 
-include $(TOPDIR)/config.mk
-
 $(shell mkdir -p $(obj)../../nvidia/common)
 
-LIB	= $(obj)lib$(BOARD).o
-
-COBJS-y	:= $(BOARD).o
+obj-y	:= paz00.o
 
 include ../../nvidia/common/common.mk
-
-COBJS	:= $(COBJS-y)
-SRCS	:= $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-
-$(LIB):	$(obj).depend $(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################