net: hinic: remove unused functions

hinic_hwdev_max_num_qpas() and hinic_msix_attr_get() are no longer called,
remove them. Also the macro HINIC_MSIX_ATTR_GET is also not called, remove
it.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>