platform/x86: oxpec: Fix turbo register for G1 AMD

platform/x86: oxpec: Fix turbo register for G1 AMD

Turns out that the AMD variant of the G1 uses different EC registers
than the Intel variant. Differentiate them and apply the correct ones
to the AMD variant.

Fixes: b369395c895b ("platform/x86: oxpec: Add support for the OneXPlayer G1")
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Link: https://lore.kernel.org/r/20250718163305.159232-1-lkml@antheas.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>