ASoC: Sort LM4857 with the CODECs in the Makefile

Having a separate list for amps is a little confusing now the official
driver model for them is the same as for other CODECs so let's sort them
into the CODEC list, but only do this for those that are actual CODEC
drivers so it's easier to remember which ones need updating.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>