media: av7110: avoid 2038 overflow in debug print

Using the deprecated do_gettimeofday() in print_time() will overflow
in 2038 on 32-bit architectures. It'sbetter to use a structure that
is safe everywhere. While we're at it, fix the missing leading zeroes
on the sub-second portion.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>