platform/x86: oxpec: Move hwmon/oxp-sensors to platform/x86

platform/x86: oxpec: Move hwmon/oxp-sensors to platform/x86

The EC of OneXPlayer devices used to only control the fan. This is no
longer the case, with the EC of OneXPlayer gaining additional
functionality (turbo button, turbo led, battery controls).

As it will be beneficial from a complexity perspective to retain this
driver as a single unit, move it out of hwmon, and into platform/x86.
Also, remove the hwmon documentation to prepare moving it to
Documentation/ABI/.

While at it, add myself to the maintainer's file.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Derek J. Clark <derekjohn.clark@gmail.com>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Link: https://lore.kernel.org/r/20250425111821.88746-4-lkml@antheas.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>