sfc: correct kernel-doc complaints

sfc: correct kernel-doc complaints

Fix kernel-doc warnings by adding 3 missing struct member descriptions
in struct efx_ef10_nic_data and removing preprocessor directives (which
are not handled by kernel-doc).

Fixes these 5 warnings:
Warning: drivers/net/ethernet/sfc/nic.h:158 bad line: #ifdef CONFIG_SFC_SRIOV
Warning: drivers/net/ethernet/sfc/nic.h:160 bad line: #endif
Warning: drivers/net/ethernet/sfc/nic.h:204 struct member 'port_id'
 not described in 'efx_ef10_nic_data'
Warning: drivers/net/ethernet/sfc/nic.h:204 struct member 'vf_index'
 not described in 'efx_ef10_nic_data'
Warning: drivers/net/ethernet/sfc/nic.h:204 struct member 'licensed_features'
 not described in 'efx_ef10_nic_data'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20260106173224.2010703-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>