ASoC: sgtl5000: Remove leading zero from '@0a' notation

Improve the binding example by removing the leading 0 from '@0a' notation,
which fixes the following build warning:

Warning (unit_address_format): Node /sgtl5000@0a unit name should not have leading 0s

Signed-off-by: Marco Franchi <marco.franchi@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>