Revert "thermal/core: Rename 'trips' to 'num_trips'"

This reverts commit bd0ea77e which is
commit e5bfcd30 upstream.

It is part of a patch series applied to 5.15.91 that breaks the Android
kernel ABI.  If it is really needed, it can be brought back in an
abi-safe way in the future.

Bug: 161946584
Change-Id: Iaa6833a61bcb425a43e64febdac73cb45da503d8
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>