cxl: Convert cxl_internal_send_cmd() to use 'struct cxl_mailbox' as input

With the CXL mailbox context split out, cxl_internal_send_cmd() can take
'struct cxl_mailbox' as an input parameter rather than
'struct memdev_dev_state'. Change input parameter for
cxl_internal_send_cmd() and fixup all impacted call sites.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://patch.msgid.link/20240905223711.1990186-4-dave.jiang@intel.com


Signed-off-by: Dave Jiang <dave.jiang@intel.com>