Remove toolcheck from generic clean targets for symbian-sbsv2

Remove toolcheck from generic clean targets for symbian-sbsv2

Toolcheck can cause generic clean fail (i.e. "make clean" or
"make debug-clean") for e.g. environments where Carbide command
line tools have not been installed, because sbsv2 toolchain does a
check for all tools related to target platforms, even though they are
not needed for actual cleaning.

Task-number: QTBUG-16691
Reviewed-by: Janne Koskinen