drivers: net: cpsw: fix compilation error with cpsw driver

drivers/net/ethernet/ti/cpsw.c: In function 'cpsw_suspend':
drivers/net/ethernet/ti/cpsw.c:1979:26: error: 'priv' undeclared (first use in this function)
drivers/net/ethernet/ti/cpsw.c:1979:26: note: each undeclared identifier is reported only once for each function it appears in
make[4]: *** [drivers/net/ethernet/ti/cpsw.o] Error 1

The compilation error was introduced by the following commit
6d3d76f8

 (drivers: net: cpsw: fix cpsw clock gating issue across suspend/resume)

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>