V4L/DVB (6226): dvb-pll: pass fe pointer into dvb_pll_configure() and set() functions

The pll-specific set() function will need access to the dvb_pll_priv
structure for new functionality.  This patch gives access to this
structure to the required functions.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>