ASoC: rt5645: set in2_diff flag for GPD win and pocket devices

The GPD pocket has a differential signal microphone and needs in2_diff
to be set to avoid getting a very noisy signal.

Since the GPD pocket and win use the same DMI strings, they share their
platform data-definition, so enabling in2_diff on the pocket also sets
it on the GPD win. The GPD win has a normal microphone, but setting
in2_diff there does not negatively impact the sound from the microphone.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>