powerpc/p5040: fix dtb build warning of p5040ds.dtb

powerpc/p5040: fix dtb build warning of p5040ds.dtb

Device node adt7461 was wrongly added in p5040ds.dts, it should be added
into i2c instead of localbus, when build p5040ds.dtb, a warning will dump:

Warning (reg_format): "reg" property in
/localbus@ffe124000/nand@2,0/adt7461@4c has invalid length (4 bytes)
(#address-cells == 1, #size-cells == 1)

This was introduced by:

commit ea6b1ba692bcb5f6e39f409a78cf8b04fdf23baa
Author: Jia Hongtao <B38951@freescale.com>
Date:   Tue Aug 28 10:00:55 2012 +0800

    powerpc: add adt7461 thermal monitor support to applicable boards

    Add thermal monitor support to following boards:
    P1022DS, MPC8536DS, P2041RDB, P3041DS, P4080DS, P5020DS, P5040DS

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>