esoc: Notify mdm-helper about the modem's error fatal

There is no way for the mdm-helper to know that the
modem has crashed to take necessary action.
Hence, added the support that sends a notification to the
user-space, through IOCTL, as and when the modem sends an
error fatal interrupt to the driver.

Change-Id: I0a596763b310641d4c9e93d03690ba96162515ff
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>