tea5767 has several possible configurations. Before the patch, the
driver were assuming the more common configuration. However, some newer
cards, like MSI @nyware Master requires other configurations, like
de-activating a gpio port and changing chip Xtal.

This patch adds the capability of altering device configuration at
runtime. This may also be used later to activate some features like
auto-mute when signal is weak.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>