V4L/DVB (13217): tda18271: handle rf_cal_on_startup properly during attach

If rf_cal_on_startup is enabled in the structure passed into
tda18271_attach, and the cal module option isn't disabled, then we
should run the initialization and calibration procedures during the
tda18271_attach function call, regardless of how many instances of the
driver have been attached.  If the device is already calibrated, the
driver will detect that and will only calibrate again if necessary.

Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>