V4L/DVB (5361): Dvb-pll: Fix Kconfig files and allow dvb-pll to be optional

A number of drivers selected DVB_PLL when they did not need it, and some
that did need it did not select it.

The DVB_PLL option is given a name and help text, so that it will show up
in the config menu.  DVB_PLL support can be turned on if an out-of-tree
driver needs it.

The standard dvb fe customization support is added to dvb-pll.h.  Since
all modules which select DVB_PLL do so unconditionally, it is not
possible to turn dvb-pll off when an enabled module selects it, unlike
most of the other frontend/tuner drivers.  This is because the users of
dvb-pll have static references to dvb-pll symbols other than the attach
function.  If these references are removed, then dvb-pll will be
disablable as the other frontend/tuner drivers are.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/dvb-pll.h b/drivers/media/dvb/frontends/dvb-pll.h
index 681186a..a5bd928 100644
--- a/drivers/media/dvb/frontends/dvb-pll.h
+++ b/drivers/media/dvb/frontends/dvb-pll.h
@@ -59,9 +59,20 @@
  * @param desc dvb_pll_desc to use.
  * @return Frontend pointer on success, NULL on failure
  */
+#if defined(CONFIG_DVB_PLL) || (defined(CONFIG_DVB_PLL_MODULE) && defined(MODULE))
 extern struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe,
 					   int pll_addr,
 					   struct i2c_adapter *i2c,
 					   struct dvb_pll_desc *desc);
+#else
+static inline struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe,
+					   int pll_addr,
+					   struct i2c_adapter *i2c,
+					   struct dvb_pll_desc *desc)
+{
+	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __FUNCTION__);
+	return NULL;
+}
+#endif
 
 #endif