[NET] smc91x: remove "irq_flags" from "struct smc91x_platdata"

IRQ trigger type can be specified in the IRQ resource definition by
IORESOURCE_IRQ_*, we need only one way to specify this.

This also fixes the following small issue:

To allow dynamic support for multiple platforms, when those relevant
macros are not defined for one specific platform, the default case
will be:

	- SMC_DYNAMIC_BUS_CONFIG defined
	- and SMC_IRQ_FLAGS = IRQF_TRIGGER_RISING

While if "irq_flags" is missing when defining the smc91x_platdata,
usually as follows:

  static struct smc91x_platdata xxxx_smc91x_data = {
	.flags	= SMC91X_USE_XXBIT,
  };

The lp->cfg.irq_flags will always be overriden by the above structure
(due to a memcpy), thus rendering lp->cfg.irq_flags to be "0" always.
(regardless of the default SMC_IRQ_FLAGS or IORESOURCE_IRQ_* flags)

Fixes this by forcing to use IORESOURCE_IRQ_* flags if present, and
make the only user of smc91x_platdata.irq_flags (renesas/migor) to
use IORESOURCE_IRQ_*.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>