ASoC: wcd9xxx: Fix disable of clock block

When the external clock to the codec is disabled, the clock gating
internal to the codec also needs to be disabled to avoid any
stability issues. Fix the disable of clock block for the codec to
gate the clock internally to codec whenever external clock is disabled

CRs-fixed: 551937
Change-Id: Iad6962bbed6ca62a6d7f2748676306084ef5c08d
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>