media: replace strcpy() by strscpy()

The strcpy() function is being deprecated upstream. Replace
it by the safer strscpy().

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>