This patch adds/modifies:
        - fix system-wide in UP mode
        - adds defaults values for all PMC/PMD in the pfm_reg_desc tables
        - adds bitmask of reserved fields for all PMC/PMD in the pfm_reg_desc
          tables
        - on McKinley ensures that reserved fields in PMC keep their initial
          values
        - ia64_reset_pmu() renamed pfm_reset_pmu()
        - pfm_pmu_snapshot() and reset_pmcs[] are gone
        - use pfm_reg_desc for defaults values anywhere it is needed
        - we now reinitialize all PMC to their default value when the kernel
          initializes perfmon on each CPU. That's needed because we have no
          guarantee there are still in the power-up state when kernel gets
          control.
        - /proc/perfmon now shows dcr_pp/pfm_syst_wide for ALL CPUs
        - adds a perfmon_generic.h in case neither CONFIG_ITANIUM nor
          CONFIG_MCKINLEY are defined