makefile: don't hardcore install utility location

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/Makefile.in

@@ -181,7 +181,7 @@ ifeq ($(BR2_STRIP_none),y)
 TARGET_STRIP=true -Not_stripping
 STRIPCMD=$(TARGET_STRIP)
 endif
-INSTALL=/usr/bin/install
+INSTALL=$(shell which install || type -p install)
 FLEX:=$(shell which flex || type -p flex)
 BISON:=$(shell which bison || type -p bison)