ASoC: dapm: Fix double lock of dapm mutex

snd_soc_dapm_force_enable_pin takes the dapm mutex
internally and then calls into the function
snd_soc_dapm_force_enable_pin_unlocked, where the mutex
is again acquired resulting into a deadlock. Fix
the double lock by not acquiring the mutex within
the unlocked version of the function.

Change-Id: I6c68f1ef1645997bbcb1e5b197652c41baa609d3
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>