ASoC: codecs: Axe some dead code in 'wcd_mbhc_adc_hs_rem_irq()'

'hphpa_on' is know to be false, so this is just dead code that should be
removed.

Suggested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/57a89cc31eb2312addd3c77896d7df8206aef138.1635967035.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown <broonie@kernel.org>