package/apcupsd: disable docs

We can skip building docs by only running make against subdirs that are
not "doc".

Fixes:
http://autobuild.buildroot.net/results/e65/e65c23c3c1cae9aa9d697323fabf8a6f310fc3ba/build-end.log

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/apcupsd/apcupsd.mk

@@ -64,4 +64,14 @@ else
 APCUPSD_CONF_OPTS += --disable-usb
 endif
 
+define APCUPSD_BUILD_CMDS
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/src
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/platforms
+endef
+
+define APCUPSD_INSTALL_TARGET_CMDS
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/src DESTDIR=$(TARGET_DIR) install
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/platforms DESTDIR=$(TARGET_DIR) install
+endef
+
 $(eval $(autotools-package))