standardize QPA input event logging category hierarchy

If qtlogging.ini contains a rule
qt.qpa.input*=true
then all available input event logging will be enabled on any platform.
There are more specific categories for touch, tablet, gestures,
input methods etc. on some platforms.

Change-Id: I8754ce23df8f0b750a4b7dfcf3afe5bab800ead8
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>