ppc4xx: Use CFG_4xx_GPIO_TABLE to configure Sequoia board

Note: this patch changes the configuration of some GPIO registers:

   Register      Old Value   New Value
---------------  ----------  ----------
DCR GPIO0_TCR    0x0000000F  0x0000F0CF
DCR GPIO0_TSRH   0x55005000  0x00000000
DCR GPIO1_TCR    0xC2000000  0xE2000000
DCR GPIO1_TSRL   0x0C000000  0x00200000
DCR GPIO1_ISR2L  0x00050000  0x00110000

Signed-off-by: Larry Johnson <lrj@acm.org>