Fix build errors when MACSEC=m and OCTEONTX2_PF=y by having
OCTEONTX2_PF depend on MACSEC if it is enabled. By adding
"|| !MACSEC", this means that MACSEC is not required -- it can
be disabled for this driver.

drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.o: in function `otx2_remove':
../drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c:(.text+0x2fd0): undefined reference to `cn10k_mcs_free'
mips64-linux-ld: drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.o: in function `otx2_mbox_up_handler_mcs_intr_notify':
../drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c:(.text+0x4610): undefined reference to `cn10k_handle_mcs_event'
Reported-by: kernel test robot <lkp@intel.com>
Fixes: c54ffc73 ("octeontx2-pf: mcs: Introduce MACSEC hardware offloading")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Subbaraya Sundeep <sbhatta@marvell.com>
Cc: Sunil Goutham <sgoutham@marvell.com>
Cc: Geetha sowjanya <gakula@marvell.com>
Cc: hariprasad <hkelam@marvell.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>