pulseaudio: improve enabling/disabling of Bluez4/Bluez5

pulseaudio: improve enabling/disabling of Bluez4/Bluez5

Instead of letting the configure script automatically detect the
presence of bluez package files, the script is now explicitly
instructed to enable or disable bluez (both 4.x and 5.x) support based
on the selection of the following packages: bluez_utils, bluez5_utils
and sbc.

Indeed, the bluez_utils or bluez5_utils packages were not sufficient
to enable Bluetooth support, the sbc package is also needed, but when
no --enable option is passed, the configure script silently disables
Bluetooth support if one of the dependencies is missing.

Signed-off-by: Calin Crisan <ccrisan@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>