cxgb4vf: update kernel-doc line comments

Update several kernel-doc line comments to fix warnings reported by
make W=1.

Fixes following class of warnings reported by make W=1 in several
places:
cxgb4vf_main.c:275: warning: Function parameter or member 'persistent'
not described in 'cxgb4vf_change_mac'
cxgb4vf_main.c:275: warning: Excess function parameter 'persist'
description in 'cxgb4vf_change_mac'

Fixes: 16f8bd4b ("cxgb4vf: Add core T4 PCI-E SR-IOV Virtual Function hardware definitions and device communication code")
Fixes: c6e0d914 ("cxgb4vf: Add T4 Virtual Function Scatter-Gather Engine DMA code")
Fixes: e0a8b34a ("cxgb4vf: Add and initialize some sge params for VF driver")
Fixes: c3168cab ("cxgb4/cxgbvf: Handle 32-bit fw port capabilities")
Fixes: 0e23daeb ("drivers/net: chelsio/cxgb*: Convert timers to use timer_setup()")
Fixes: 3f8cfd0d ("cxgb4/cxgb4vf: Program hash region for {t4/t4vf}_change_mac()")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>