When the DoubleSpeed or QuadSpeed bit is set, the SingleSpeed frequency has to be multiplied accordingly. Since this functionality will be required at least twice, refactor it into a separate function. The second reference to the newly introduced hdspm_rate_multiplier() will be in a separate commit. Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>