n_gsm.c : Open gsmtty in blocking mode whitout taking count of Carrier Detect

n_gsm.c : Open gsmtty in blocking mode whitout taking count of Carrier Detect

BZ: 28988

Some modem (IMC, but other as well) do not set CD when DLCI for AT command are
opened. CLOCAL can't be used before the first open, as file descriptor is
needed (fd is given once CD is received)

We add here a new parameter to the MUX during initialization IOCTL.
Parameter name : clocal.
clocal = 1 : Force CLOCAL, ie. do not wait for Carrier Detect from modem
clocal = 0 : Wait for Carrier Detect from modem

Default value in MUX is 1.

As tty_port_block_til_ready will exit due to CLOCAL, we need also to wait UA
from modem. We have also to wait UA in gsmtty_close.

CLOCAL can be unset later as usual.

Change-Id: I01d78449dac3d21196aaa8f4f984baf8a3fb578f
Signed-off-by: Vincent Pillet <vincentx.pillet@intel.com>
Reviewed-on: http://android.intel.com:8080/51984
Reviewed-by: Predon, Frederic <frederic.predon@intel.com>
Reviewed-by: Lebsir, SamiX <samix.lebsir@intel.com>
Tested-by: Lebsir, SamiX <samix.lebsir@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>