cxgb3: Remove unused declarations

Commit 4d22de3e ("Add support for the latest 1G/10G Chelsio adapter,
T3.") declared but never implemented these.
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h

@@ -106,6 +106,4 @@ static inline struct t3c_tid_entry *lookup_atid(const struct tid_info *t,
 	return &e->t3c_tid;
 }
 
-int attach_t3cdev(struct t3cdev *dev);
-void detach_t3cdev(struct t3cdev *dev);
 #endif