ionic: Remove unused declarations

ionic: Remove unused declarations

Commit fbfb8031533c ("ionic: Add hardware init and device commands")
declared but never implemented ionic_q_rewind()/ionic_set_dma_mask().
Commit 969f84394604 ("ionic: sync the filters in the work task")
declared but never implemented ionic_rx_filters_need_sync().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20230821134717.51936-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>