Setting the vibrator enable_mask is not implemented correctly:

For regmap_update_bits(map, reg, mask, val) we give in either
regs->enable_mask or 0 (= no-op) as mask and "val" as value.
But "val" actually refers to the vibrator voltage control register,
which has nothing to do with the enable_mask.

So we usually end up doing nothing when we really wanted
to enable the vibrator.

We want to set or clear the enable_mask (to enable/disable the vibrator).
Therefore, change the call to always modify the enable_mask
and set the bits only if we want to enable the vibrator.

Fixes: d4c7c5c9 ("Input: pm8xxx-vib - handle separate enable register")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20200114183442.45720-1-stephan@gerhold.netSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>