embedded.mk: move dependencies to sepolicy

Some selinux build packages are defined in embedded.mk,
others are defined in system/sepolicy/Android.mk. Move all
to sepolicy as a dependency of the phony package selinux_policy
which is defined in embedded.mk.

Test: build Marlin (Treble) and Angler (non-Treble)
Merged-In: I734c2909354349d146c6f78beb74bd990d9af30d
Change-Id: I734c2909354349d146c6f78beb74bd990d9af30d