To reduce the code size and make the code clearer, replace all
roce_get_xxx() with hr_reg_read() to read the data fields.

Link: https://lore.kernel.org/r/20220512080012.38728-3-liangwenpeng@huawei.comSigned-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>