Use split-long-arguments to touch pdk platform.zip files

touch $(_pdk_fusion_files) is too long for some systems, use
split-long-arguments to execute touch multiple times with a
subset of the list of files.

Change-Id: I8e8c6770936337b93e0fdf381eca8c79fd722523
diff --git a/core/pdk_config.mk b/core/pdk_config.mk
index f3dbe55..0949c38 100644
--- a/core/pdk_config.mk
+++ b/core/pdk_config.mk
@@ -46,7 +46,8 @@
 	@echo "Unzip $(dir $@) <- $<"
 	$(hide) rm -rf $(dir $@) && mkdir -p $(dir $@)
 	$(hide) unzip -qo $< -d $(dir $@)
-	$(hide) touch $@ $(_pdk_fusion_files)
+	$(hide) touch $@
+	$(call split-long-arguments,touch,$(_pdk_fusion_files))
 
 _pdk_fusion_file_list := $(shell unzip -Z -1 $(PDK_FUSION_PLATFORM_ZIP) '*[^/]' 2>/dev/null)
 _pdk_fusion_files := $(addprefix $(_pdk_fusion_intermediates)/, $(_pdk_fusion_file_list))