arm64: mm: Update perf accounting to handle poison faults

Re-organise the perf accounting for fault handling in preparation for
enabling handling of hardware poison faults in subsequent commits. The
change updates perf accounting to be inline with the behaviour on
x86.

With this update, the perf fault accounting -

  * Always report PERF_COUNT_SW_PAGE_FAULTS

  * Doesn't report anything else for VM_FAULT_ERROR (which includes
    hwpoison faults)

  * Reports PERF_COUNT_SW_PAGE_FAULTS_MAJ if it's a major
    fault (indicated by VM_FAULT_MAJOR)

  * Otherwise, reports PERF_COUNT_SW_PAGE_FAULTS_MIN

Change-Id: I4be2180ef9d046fb4f8edcbcc9dc30ce0c6622d2
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: improbir <ghosh_probir@yahoo.com>