ASoC: Skip noop reconfiguration of WM8958 DSP2 algorithms

If we're setting the currently applied value for one of the DSP algorithm
configurations we can just skip all the handling as the control set is a
noop. This ensures we do not disrupt a running DSP.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Cc: stable@kernel.org