platform/x86/dell: dell-pc: Create platform device

platform/x86/dell: dell-pc: Create platform device

In order to have a device for the platform profile core to reference
create a platform device for dell-pc.

While doing this change the memory allocation for the thermal handler
to be device managed to follow the lifecycle of that device.

Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241206031918.1537-3-mario.limonciello@amd.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>