platform/chrome: cros_usbpd_notify: Amend ACPI driver to plat

Convert the ACPI driver into the equivalent platform driver, with the
same ACPI match table as before. This allows the device driver to access
the parent platform EC device and its cros_ec_device struct, which will
be required to communicate with the EC to pull PD Host event information
from it.

Also change the ACPI driver name to "cros-usbpd-notify-acpi" so that
there is no confusion between it and the "regular" platform driver on
platforms that have both CONFIG_ACPI and CONFIG_OF enabled.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>