drivers/perf: hisi: Extract initialization of "cpa_pmu->pmu"

Use hisi_pmu_init() function to simplify initialization of "cpa_pmu->pmu".

Signed-off-by: Junhao He <hejunhao3@huawei.com>
Link: https://lore.kernel.org/r/20230119100307.3660-4-hejunhao3@huawei.com


Signed-off-by: Will Deacon <will@kernel.org>