msm: camera: flash: enable gpio-based flash

When enable gpio-based flash , not need to enable
regulator for it ,so we need to bypss enable regulator
error.

CRs-Fixed: 2590826.

Change-Id: I26488fe3c5bfed75dee45188f1dccca9d613d310
Signed-off-by: Lei Wang <wangwanglei@codeaurora.org>