Add is-board-platform2/is-board-platform-in-list2

This is the first step to get rid of the set of identical macros defined
in utils.mk files in multiple device/google/xxxx directories. The macros
is-board-platform/is-board-platform-in-list will be eventuall replaced
with the new ones.

Bug: 190051051
Test: treehugger
Change-Id: I28017df86dbd899be38f882dd5496c894986d8db