crypto: hisilicon/qm - fix 'QM_XEQ_DEPTH_CAP' mask value

'QM_XEQ_DEPTH_CAP' mask value is GENMASK(31, 0) instead of GENMASK(15, 0).
If the mask value is incorrect, will cause abnormal events cannot be
handled. So fix it.

Fixes: 129a9f34 ("crypto: hisilicon/qm - get qp num and depth from hardware registers")
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>