platform/x86: thinkpad_acpi: Drop tpacpi_input_send_key_masked() and hotkey_driver_event()

Both are only 1 / 2 lines and both only have 1 caller fold the contents
into tpacpi_hotkey_send_key() which is their single caller.

Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240424122834.19801-13-hdegoede@redhat.com