systemc: Exclude two more tests which have undefined functions.
systemc: Exclude two more tests which have undefined functions.

It seems that implementing more of systemc makes the compiler think it
wants an implementation, and so the build fails with linker errors.

Change-Id: I6f0b031f300b0ad60dac8b4462b8f4d466aa7dfa
Reviewed-on: https://gem5-review.googlesource.com/12081
Reviewed-by: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>
Maintainer: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>

gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu