platform/x86: hp_accel: Convert to be a platform driver

platform/x86: hp_accel: Convert to be a platform driver

ACPI core in conjunction with platform driver core provides
an infrastructure to enumerate ACPI devices. Use it in order
to remove a lot of boilerplate code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20210823093222.19544-3-andriy.shevchenko@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>