drm/msm/a7xx: allow writing to CP_BV counter selection registers

In addition to the CP_PERFCTR_CP_SEL register range, allow writes to the
CP_BV_PERFCTR_CP_SEL registers in the 0x8e0-0x8e6 range for profiling
purposes of tools like fdperf and perfetto.

Signed-off-by: Zan Dobersek <zdobersek@igalia.com>
Patchwork: https://patchwork.freedesktop.org/patch/580548/
[fixup a730_protect size]
Signed-off-by: Rob Clark <robdclark@chromium.org>