perf: arm_cspmu: ampere_cspmu: Add support for Ampere SoC PMU

Ampere SoC PMU follows CoreSight PMU architecture. It uses implementation
specific registers to filter events rather than PMEVFILTnR registers.

Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20230913233941.9814-5-ilkka@os.amperecomputing.com


[will: Include linux/io.h in ampere_cspmu.c for writel()]
Signed-off-by: Will Deacon <will@kernel.org>