platform/x86: oxpec: add support for OneXPlayer Super X

OneXPlayer Super X identifies itself via DMI as:

  board vendor: ONE-NETBOOK
  board name:   ONEXPLAYER SUPER X
  product name: ONEXPLAYER SUPER X

Current mainline oxpec does not contain a matching DMI entry for this
system, so the in-tree driver is not auto-loaded.

On the tested Super X device, the working EC layout matches the
following handling:

- fan RPM is read from OXP_SENSOR_FAN_REG (0x76)
- pwm1_enable uses OXP_SENSOR_PWM_ENABLE_REG (0x4A)
- pwm1 uses OXP_SENSOR_PWM_REG (0x4B) with direct 0-255 writes
- turbo toggle uses OXP_TURBO_SWITCH_REG (0xF1)
- charge-limit / charge-behaviour uses the same battery extension path
  as the X1 family

Add a dedicated oxp_superx board id, a DMI match for OneXPlayer Super X,
and route the fan, PWM, turbo-toggle, and battery-extension paths
through the validated Super X handling.

Tested-on: OneXPlayer Super X
Signed-off-by: ps1x <ps1x@users.noreply.github.com>
