UPSTREAM: arm64: perf: Abstract system register accesses away

As we want to enable 32bit support, we need to distanciate the
PMUv3 driver from the AArch64 system register names.

This patch moves all system register accesses to an architecture
specific include file, allowing the 32bit counterpart to be
slotted in at a later time.

Change-Id: Ib5c22a45d2b0ed844ee7d03cb7a7fa855230fcca
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Co-developed-by: Zaid Al-Bassam <zalbassam@google.com>
Signed-off-by: Zaid Al-Bassam <zalbassam@google.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230317195027.3746949-3-zalbassam@google.com


Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit df29ddf4)
Signed-off-by: Danesh Petigara <danesh.petigara@broadcom.com>