make.sh: copy capstone.pc to the right dir for pkgconfig. adapted from patches of Ben Nagy & Pancake
diff --git a/Makefile b/Makefile
index db2344b..ecc3d5d 100644
--- a/Makefile
+++ b/Makefile
@@ -197,7 +197,7 @@
 LIBOBJ += MCInst.o
 
 
-PKGCFGDIR = $(LIBDATADIR)/pkgconfig
+PKGCFGDIR ?= $(LIBDATADIR)/pkgconfig
 API_MAJOR=$(shell echo `grep -e CS_API_MAJOR include/capstone.h | grep -v = | awk '{print $$3}'` | awk '{print $$1}')
 VERSION_EXT =