toshiba_acpi: Add Hotkey Event Type function and definitions

This patch adds support to query the "Hotkey Event Type" the system
supports.

There are two main event types (so far), 0x10 and 0x11, with the
first being all those laptops that have the old keyboard layout, and
the latter all those new laptops with the new keyboard layout.

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>