ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs

Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used,
all PCC registers, for all processors in the same performance domain
(as defined by _PSD), must be defined to be in the same subspace.

Based on Section 14.1 of ACPI specification, it is possible to have a
maximum of 256 PCC subspace IDs. Add support of multiple PCC subspace
ID instead of using a single global pcc_data structure.

While at that, fix the time_delta check in send_pcc_cmd() so that
last_mpar_reset and mpar_count are initialized properly.

Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>