Reading the signature of CS8427 over SPI/I2C fails on some devices
by mysterious reason.  In most cases, however, it succeeds at the
sequential read.  So, let's give a second chance to check the signature
again.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>