Currently handling of kernel_append_params is very inconsistent. This
change applies a straightforward process:
1. instance_info[kernel_append_params]
2. driver_info[kernel_append_params]
3. [pxe]kernel_append_params (renamed from pxe_append_params).
Also adds a helper for subsequent fixes in other drivers.
Change-Id: I79bcf4d8ef1f0f55a82e0991dd5bb1685b3f7957
Story: #2008902
Task: #42469
2a73f5a84e