MIPS: TXx9: Fix quirk_slc90e66_ide

Fix wrong code spotted by -Werror=array-bounds:
	arch/mips/txx9/generic/pci.c:334:23: error: array subscript is above array bounds [-Werror=array-bounds]
	  pci_write_config_byte(dev, regs[i], dat);

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7214/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>