Expose the following functions 'lan966x_hw_offload',
'lan966x_ifh_get_src_port' and 'lan966x_ifh_get_timestamp' in
lan966x_main.h so they can be accessed by FDMA.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>