ANDROID: kbuild: do not merge .section..* into .section in modules

Sections with double dots, e.g. .data..percpu are named intentionally
to avoid matching rules that apply to .section.*. Change module section
merging rules to skip these.

Bug: 151981957
Change-Id: I23787aa40d69da1c6ca622a5f111704d2459e163
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>