octeontx2-af: Remove redundant functions rvu_npc_exact_mac2u64()

The rvu_npc_exact_mac2u64() is used to convert an Ethernet MAC address
into a u64 value, as this is exactly what ether_addr_to_u64() does.
Use ether_addr_to_u64() to replace the rvu_npc_exact_mac2u64().

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Acked-by: Geethasowjanya Akula <gakula@marvell.com>
Link: https://lore.kernel.org/r/20230808114504.4036008-4-lizetao1@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>