liquidio: moved liquidio_legacy_intr_handler to lio_core.c

Moving liquidio_legacy_intr_handler to lio_core.c

Signed-off-by: Intiyaz Basha <intiyaz.basha@cavium.com>
Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>