feat(git-hooks): add pre-commit hook

Adds a pre-commit git hook to keep track of copyright year.
Checks staged files for Arm copyright header and suggests a change if
the year is outdated. Works with both single-year format and
from_year-to_year format.

Signed-off-by: Maksims Svecovs <maksims.svecovs@arm.com>
Change-Id: If81a0b9f5e047ec0ac401c7cf1792b9da6644926