perf: riscv: Fix selecting counters in legacy mode

It is required to check event type before checking event config.
Events with the different types can have the same config.
This check is missed for legacy mode code

For such perf usage:
    sysctl -w kernel.perf_user_access=2
    perf stat -e cycles,L1-dcache-loads --
driver will try to force both events to CYCLE counter.

This commit implements event type check before forcing
events on the special counters.

Signed-off-by: Shifrin Dmitry <dmitry.shifrin@syntacore.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Fixes: cc4c07c8 ("drivers: perf: Implement perf event mmap support in the SBI backend")
Link: https://lore.kernel.org/r/20240729125858.630653-1-dmitry.shifrin@syntacore.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>