QNX notification value fix

1.) Implemented proper conversion to hexadecimal value.
2.) Error was emitted in case of value assignment and it is
fixed now.

Change-Id: Ifb6220a6379b350eaa8bb67841a5029ecc55cad2
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Unused error enums removed

Emitting errors is done by QLowEnergyController class.
These enums were not used.

Change-Id: I7883ee16ce67bf6ae06916ae7789efe802c098d6
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>