Input: apple_z2 - fix reading incorrect reports after exiting sleep

Input: apple_z2 - fix reading incorrect reports after exiting sleep

Under certain conditions (more prevalent after a suspend/resume cycle),
the touchscreen controller can send the "boot complete" interrupt before
it actually finished booting. In those cases, attempting to read touch
data resuls in a stream of "not ready" messages being read and
interpreted as a touch report. Check that the response is in fact a
touch report and discard it otherwise.

Reported-by: pitust <piotr@stelmaszek.com>
Closes: https://oftc.catirclogs.org/asahi/2025-12-17#34878715;
Fixes: 471a92f8a21a ("Input: apple_z2 - add a driver for Apple Z2 touchscreens")
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Link: https://patch.msgid.link/20251218-z2-init-fix-v1-1-48e3aa239caf@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>