time64: Rename to a .inc file to match the others

I meant to do this whilst merging but messed up the patches. This
file is a .inc file and should match the others.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/conf/distro/include/time64.conf b/meta/conf/distro/include/time64.inc
similarity index 100%
rename from meta/conf/distro/include/time64.conf
rename to meta/conf/distro/include/time64.inc