ASoC: cs4271: Fix build error without CONFIG_SPI_MASTER

cs4271_common_probe() is called from cs4271_i2c_probe() but defined in
CONFIG_SPI_MASTER block, thus it results in a build error when
CONFIG_SPI_MASTER=n:
  sound/soc/codecs/cs4271.c:721:2: error: implicit declaration of function ‘cs4271_common_probe’ [-Werror=implicit-function-declaration]

Move the function out of #if block.

Fixes: d6cf89ee ('ASoC: cs4271: claim reset GPIO in bus probe function')
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Daniel Mack <daniel@zonque.org>
Acked-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Mark Brown <broonie@linaro.org>