powerpc/papr_scm: trivial: fix typo in a comment

There is a spelling mistake "byes" -> "bytes" in a comment of
function drc_pmem_query_stats(). Fix that typo.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210418074003.6651-1-kjain@linux.ibm.com