ARM: dts: imx6qdl-hummingboard2: Remove leading zero in unit address

Remove the leading zero from unit address to fix the following build
warning with W=1:

arch/arm/boot/dts/imx6dl-hummingboard2.dtb: Warning (unit_address_format): Node /soc/aips-bus@2100000/i2c@21a0000/codec@0a unit name should not have leading 0s

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>