[FEATURE] Add DSP support to QEMU HDA driver

[kv2019i]

QEMU has a base HDA driver, but this lacks DSP support. To support it, following changes would be needed:

• add the PCI IDs for SKL+
• Reporting the DSP bit in HDA capabilities
• Adding the host IPC registers to HDA side.

Note: based on initial task list from @lgirdwood