Input: add input-event-codes header file

Add input-event-codes header file and move all type and axis defines
there.

The purpose of this new header file is to have a single canonical source
for event-codes which can be used outside of C-code too. One example of
such usage is the use of event-codes in devicetree source files.

Change-Id: Ie66a4ce9dab38c3fc51a5bff63c0b589a82ae6d3
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Git-commit: f902dd893427eade90f7eaf858e5ff8b150a5a12
Git-repo: https://android.googlesource.com/kernel/common/


[spathi@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>