platform/mellanox: mlxbf-pmc: Validate event/enable input

Before programming the event info, validate the event number received as input
by checking if it exists in the event_list. Also fix a typo in the comment for
mlxbf_pmc_get_event_name() to correctly mention that it returns the event name
when taking the event number as input, and not the other way round.

Fixes: 423c3361 ("platform/mellanox: mlxbf-pmc: Add support for BlueField-3")
Signed-off-by: Shravan Kumar Ramani <shravankr@nvidia.com>
Reviewed-by: David Thompson <davthompson@nvidia.com>
Link: https://lore.kernel.org/r/2ee618c59976bcf1379d5ddce2fc60ab5014b3a9.1751380187.git.shravankr@nvidia.com


[ij: split kstrbool() change to own commit.]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>