platform/x86: thinkpad_acpi: Drop KEY_RESERVED special handling

platform/x86: thinkpad_acpi: Drop KEY_RESERVED special handling

The input core already filters out EV_KEY events for KEY_RESERVED,
remove the check for this in tpacpi_input_send_key() and rely
on the input core filtering instead.

Also change tpacpi_input_send_key() to only report the scancode
once instead of reporting it on both press and release. Together
these 2 changes make tpacpi_input_send_key() behave the same as
sparse_keymap_report_event().

The goal of this patch is to have a separate commit with
the slightly different behavior from sparse_keymap_report_event()
before switching over to using the sparse-keymap helpers.

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/20240424122834.19801-19-hdegoede@redhat.com