cxl/core: Add locked variants of the poison inject and clear funcs

cxl/core: Add locked variants of the poison inject and clear funcs

The core functions that validate and send inject and clear commands
to the memdev devices require holding both the dpa_rwsem and the
region_rwsem.

In preparation for another caller of these functions that must hold
the locks upon entry, split the work into a locked and unlocked pair.

Consideration was given to moving the locking to both callers,
however, the existing caller is not in the core (mem.c) and cannot
access the locks.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/1d601f586975195733984ca63d1b5789bbe8690f.1754290144.git.alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>