mfd: twl4030-power: Fix regression with missing compatible flag

Commit e7cd1d1e ("mfd: twl4030-power: Add generic reset
configuration") accidentally removed the compatible flag for
"ti,twl4030-power" that should be there as documented in the
binding.

If "ti,twl4030-power" only the poweroff configuration is done
by the driver.

Fixes: e7cd1d1e ("mfd: twl4030-power: Add generic reset configuration")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: "Dr. H. Nikolaus Schaller" <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>