linux-fusion: use install target instead of headers_install

The headers_install target no longer exists in the Makefile, the
installation of headers is done by the install target.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>

package/linux-fusion/linux-fusion.mk

@@ -37,7 +37,7 @@ define LINUX_FUSION_INSTALL_STAGING_CMDS
 	$(MAKE) $(TARGET_CONFIGURE_OPTS) \
 		$(LINUX_FUSION_MAKE_OPTS) \
 		INSTALL_MOD_PATH=$(STAGING_DIR) \
-		-C $(@D) headers_install
+		-C $(@D) install
 endef
 
 define LINUX_FUSION_INSTALL_TARGET_CMDS