Retire obsolete emulator targets and boards

the sdk_phone* targets are replaced with sdk_phone64*,
the emulator* boards are replaced with emu64* in
the device/generic/goldfish folder.

Bug: 295259752
Test: presubmit
Change-Id: I069a06baf02aea30db617f183abbfeaa6f968f29
Signed-off-by: Roman Kiryanov <rkir@google.com>