[media] media: dvb-core add new flag exit flag value for resume

Some fe drivers will have to do additional initialization
in their fe ops.init interfaces when called during resume.
Without the additional initialization, fe and tuner driver
resume fails. A new fe exit flag value DVB_FE_DEVICE_RESUME
is necessary to detect resume case. This patch adds a new
define and changes dvb_frontend_resume() to set it prior to
calling fe init and tuner init calls and resets it back to
DVB_FE_NO_EXIT once fe and tuner init is done.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>