ppc4xx: PPC405EP Set EMAC noise filter bits

This bug was introduced with commit aee747f1
which enabled CFG_4xx_GPIO_TABLE for PPC405 and unintentionally
disabled the setting of the emac noise filter bits for PPC405EP when CFG_4xx_GPIO_TABLE is set.

Signed-off-by: Markus Brunner <super.firetwister@gmail.com>
Signed-off-by: Stefan Roese <sr@denx.de>