The dell-smbios stack only currently uses an SMI interface which grants
direct access to physical memory to the firmware SMM methods via a pointer.

This dispatcher driver adds a WMI-ACPI interface that is detected by WMI
probe and preferred over the SMI interface in dell-smbios.

Changing this to operate over WMI-ACPI will use an ACPI OperationRegion
for a buffer of data storage when SMM calls are performed.

This is a safer approach to use in kernel drivers as the SMM will
only have access to that OperationRegion.
Signed-off-by: NMario Limonciello <mario.limonciello@dell.com>
Reviewed-by: NEdward O'Callaghan <quasisec@google.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>