cxl/mbox: Use __le32 in get,set_lsa mailbox structures

CXL specification defines these as little endian.

Fixes: 60b8f172 ("cxl/pmem: Translate NVDIMM label commands to CXL label commands")
Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/20220225221456.1025635-1-alison.schofield@intel.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>