scripts/Makefile.lib: Only apply u-boot.dtsi files in the target directory

We only want to apply files such as 'omap5-u-boot.dtsi', which resides
in arch/arm/dts/ to other files in arch/arm/dts/ and not say
test/overlay/.  Rework the make logic to check for -u-boot.dtsi files in
the same directory as their target dts.

Cc: Simon Glass <sjg@chromium.org>
Reported-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Tested-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

scripts/Makefile.lib

@@ -164,14 +164,12 @@ cpp_flags      = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(UBOOTINCLUDE)     \
 
 ld_flags       = $(LDFLAGS) $(ldflags-y)
 
-dts_dir = $(srctree)/arch/$(ARCH)/dts
-
 # Try these files in order to find the U-Boot-specific .dtsi include file
-u_boot_dtsi_options = $(wildcard $(dts_dir)/$(basename $(notdir $<))-u-boot.dtsi) \
-	$(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_SOC))-u-boot.dtsi) \
-	$(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_CPU))-u-boot.dtsi) \
-	$(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_VENDOR))-u-boot.dtsi) \
-	$(wildcard $(dts_dir)/u-boot.dtsi)
+u_boot_dtsi_options = $(wildcard $(dir $<)$(basename $(notdir $<))-u-boot.dtsi) \
+	$(wildcard $(dir $<)$(subst $\",,$(CONFIG_SYS_SOC))-u-boot.dtsi) \
+	$(wildcard $(dir $<)$(subst $\",,$(CONFIG_SYS_CPU))-u-boot.dtsi) \
+	$(wildcard $(dir $<)$(subst $\",,$(CONFIG_SYS_VENDOR))-u-boot.dtsi) \
+	$(wildcard $(dir $<)u-boot.dtsi)
 
 # Uncomment for debugging
 # $(warning u_boot_dtsi_options: $(u_boot_dtsi_options))