Fix the following gcc warnings on sparc64, when TCP_OFFLOAD is not
defined:
sys/dev/cxgbe/t4_main.c:7474: warning: 'sysctl_tp_tick' defined but not used sys/dev/cxgbe/t4_main.c:7505: warning: 'sysctl_tp_dack_timer' defined but not used sys/dev/cxgbe/t4_main.c:7519: warning: 'sysctl_tp_timer' defined but not used
This just adds a bunch of #ifdef TCP_OFFLOAD in the right places.
Reviewed by: np
Differential Revision: https://reviews.freebsd.org/D5620