via-velocity uses INET interfaces

via-velocity doesn't build when CONFIG_INET=n:

drivers/built-in.o: In function `velocity_unregister_notifier':
via-velocity.c:(.text+0xe9b46): undefined reference to `unregister_inetaddr_notifier'
drivers/built-in.o: In function `velocity_init_module':
via-velocity.c:(.init.text+0xa027): undefined reference to `register_inetaddr_notifier'

I wanted to make this change in drivers/net/Kconfig, but
this isn't legal kconfig language:

 config VIA_VELOCITY
        tristate "VIA Velocity support"
        depends on NET_PCI && PCI
+       depends on INET if PM
        select CRC32
        select CRC_CCITT
        select MII

so fix it in via-velocity.c instead.
Builds with all 4 combinations of CONFIG_NET & CONFIG_PM.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>