spi: jcore: disable clock when registering spi conroller failed

 When probe function fails in registering the spi controller, the clock
 should remain disabled.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Takuo Koguchi <takuo.koguchi.sw@hitachi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>