ASoC: sgtl5000: Clarify a bit about the ER1 meaning

The "check ER1" message is not very clear about its meaning.

Improve it a bit by referring to it as "ER1 erratum" so that it
becomes clearer that ER1 references to a SGTL5000 erratum.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>