kbuild: parameterize the .o part of suffix-search

The suffix-search macro hard-codes the suffix, '.o'.

Make it a parameter so that the multi-search and real-search macros
can be reused for foo-dtbs syntax introduced by commit 15d16d6d
("kbuild: Add generic rule to apply fdtoverlay").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/Makefile.lib

@@ -44,19 +44,22 @@ else
 obj-y		:= $(filter-out %/, $(obj-y))
 endif
 
-# Expand $(foo-objs) $(foo-y) by calling $(call suffix-search,foo.o,-objs -y)
-suffix-search = $(strip $(foreach s, $2, $($(1:.o=$s))))
+# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
+suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
+# List composite targets that are constructed by combining other targets
+multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
+# List primitive targets that are compiled from source files
+real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
+
 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
-multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2 -), $m)))
-multi-obj-y := $(call multi-search,$(obj-y),-objs -y)
-multi-obj-m := $(call multi-search,$(obj-m),-objs -y -m)
+multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
+multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
 multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
 
 # Replace multi-part objects by their individual parts,
 # including built-in.a from subdirectories
-real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2 -), $(call suffix-search, $m, $2), $m))
-real-obj-y := $(call real-search, $(obj-y),-objs -y)
-real-obj-m := $(call real-search, $(obj-m),-objs -y -m)
+real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
+real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
 
 always-y += $(always-m)