Add init_second_stage.recovery to base modules.

It was previously being included as a REQUIRED module of
the init module, but including it separately allows
separating the system and recovery artifacts in different
mk files.

Remove the whitelist entries the previous construct
necessitated.

Bug: 112318375
Test: lunch mainline_arm64 && m nothing
Change-Id: I02d9ac73c65ba58bb2acc7b2046b06b58c723ced