build: Actually build the recovery.img if !BOARD_CUSTOM_BOOTIMG_MK

Fix the BOARD_CUSTOM_BOOTIMG_MK if and call build of recovery.img
also removed unused variable RECOVERYIMAGE_EXTRA_DEPS until associated
commit is merged

Change-Id: I94f5f26bc01e03d761ccc260342f330a4a06b141
1 file changed