net: pxa168: Fix build errors by including interrupt.h

Commit a6b7a407 removed
linux/interrupt.h from netdevice.h. This fixes below build failure

drivers/net/pxa168_eth.c: In function 'pxa168_eth_collect_events':
drivers/net/pxa168_eth.c:866: error: 'IRQ_NONE' undeclared (first use in this function)
drivers/net/pxa168_eth.c:866: error: (Each undeclared identifier is reported only once
drivers/net/pxa168_eth.c:866: error: for each function it appears in.)
drivers/net/pxa168_eth.c: At top level:
drivers/net/pxa168_eth.c:913: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'pxa168_eth_int_handler'
drivers/net/pxa168_eth.c: In function 'pxa168_eth_open':
drivers/net/pxa168_eth.c:1133: error: implicit declaration of function 'request_irq'
drivers/net/pxa168_eth.c:1133: error: 'pxa168_eth_int_handler' undeclared (first use in this function)
drivers/net/pxa168_eth.c:1134: error: 'IRQF_DISABLED' undeclared (first use in this function)
drivers/net/pxa168_eth.c:1160: error: implicit declaration of function 'free_irq'

Signed-off-by: Tanmay Upadhyay <tanmay.upadhyay@einfochips.com>
Signed-off-by: David S. Miller <davem@davemloft.net>