Kerneldoc validation gets confused if syntax isn't "@.*: ".

Adding the missing colons squashes the following W=1 warnings:

 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'dev' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'locked' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'freq' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'paf' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'imeich' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'cid' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'tac' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'fac' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'svn' not described in 'ab3100_otp'
 drivers/mfd/ab3100-otp.c:60: warning: Function parameter or member 'debugfs' not described in 'ab3100_otp'

Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>