toshiba_acpi: Change *available functions return type

This patch changes the *available functions return type from int to
void.

The checks for support of their respective features are done inside
such functions and there was no need to return anything as we can
flag the queried feature as supported inside these functions.

The code was adapted accordingly to these changes and two new
variables were created and another was changed from uint to bool.

Also, the function toshiba_acceleremoter_supported was renamed to
toshiba_accelerometer_available to maintain the naming consistency on
the driver.

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