base: remove LOG_TO(), PLOG_TO() and LOG_STREAM_TO() macros

There were only two users of these and both of them were better off
setting up a default logger.

These macros are not particularly useful as it's not useful for a
single program to write to both the MAIN and SYSTEM logs.  In fact,
the opposite of these macros would be more beneficial: having more
programs write to only the MAIN or only the SYSTEM buffer, so getting
rid of these macros removes a temptation for bad behavior.

Users that absolutely need to do this behavior can still use the
liblog macros or functions, but that should be an extreme edge case,
such as the few programs that write to the CRASH buffer and does not
need to exist in libbase.

Bug: 119867234
Test: build
Change-Id: I23369c3b48ed636b617220cab47f77fdd5559763