lib/ims: Makefile - try to use pkg-config if xml2-config is not found

- GH #2199

(cherry picked from commit 58deac2e7fd62afca409b17903deb951493b213a)

src/lib/ims/Makefile

@@ -12,6 +12,12 @@ DEFS+=-DSER
 
 ifeq ($(CROSS_COMPILE),)
 XML2CFG=$(shell which xml2-config)
+ifeq ($(XML2CFG),)
+XML2CFG=$(shell \
+	if pkg-config --exists libxml-2.0; then \
+		echo 'pkg-config libxml-2.0'; \
+	fi)
+endif
 endif
 
 ifneq ($(XML2CFG),)