target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER

target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER

Add arrays to hold the registers, the definitions themselves, access
functions, and logic to reset counters when PMCR.P is set. Update
filtering code to support counters other than PMCCNTR. Support migration
with raw read/write functions.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20181211151945.29137-11-aaron@os.amperecomputing.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>