platform/x86: thinkpad_acpi: Fix for ThinkPad's with ECFW showing incorrect fan speed

[ Upstream commit 1be765b2 ]

Fix for Thinkpad's with ECFW showing incorrect fan speed. Some models use
decimal instead of hexadecimal for the speed stored in the EC registers.
For example the rpm register will have 0x4200 instead of 0x1068, here
the actual RPM is "4200" in decimal.

Add a quirk to handle this.

Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
Suggested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20241105235505.8493-1-vishnuocv@gmail.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>