net: lpc_eth: remove irq > NR_IRQS check from probe()

If the driver is used on an ARM platform with SPARSE_IRQ defined,
semantics of NR_IRQS is different (minimal value of virtual irqs) and
by default it is set to 16, see arch/arm/include/asm/irq.h.

This value may be less than the actual number of virtual irqs, which
may break the driver initialization. The check removal allows to use
the driver on such a platform, and, if irq controller driver works
correctly, the check is not needed on legacy platforms.

Fixes a runtime problem:

    lpc-eth 31060000.ethernet: error getting resources.
    lpc_eth: lpc-eth: not found (-6).

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>