src: Drop useless -I from AM_LDFLAGS in Makefile

The -I switch is meant for extending the list of paths searched
when looking for a header file. There's no justification in
having in linker flags.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/Makefile.am

 SUBDIRS := gallium/auxiliary
-AM_LDFLAGS = -lgbm -lm -ldl -I./gallium/include \
+AM_LDFLAGS = -lgbm -lm -ldl \
 	$(EPOXY_LIBS) \
 	$(CODE_COVERAGE_LDFLAGS)