drivers/perf: hisi: Fixup one DDRC PMU register offset

drivers/perf: hisi: Fixup one DDRC PMU register offset

For DDRC PMU, each PMU counter is fixed-purpose. There is a mismatch
between perf list and driver definition on rw_chg event.
# perf list | grep chg
  hisi_sccl1_ddrc0/rnk_chg/                          [Kernel PMU event]
  hisi_sccl1_ddrc0/rw_chg/                           [Kernel PMU event]
But the register offset of rw_chg event is not defined in the driver,
meanwhile bnk_chg register offset is mis-defined, let's fixup it.

Fixes: 55953d3636c2 ("perf: hisi: Add support for HiSilicon SoC DDRC PMU driver")
Cc: stable@vger.kernel.org
Cc: John Garry <john.garry@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Weijian Huang <huangweijian4@hisilicon.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>