systemc: Add some non-standard sc_trace variants.

systemc: Add some non-standard sc_trace variants.

These overloads of sc_trace take the unsigned version of some primitive
types. The compiler thought it was ambiguous how to convert an unsigned
integer value into a signed one since there were several different
functions which took signed integer parameters of various sizes.

These versions of sc_trace aren't in the standard, but they are in the
Accellera implementation and do fix building of the regression tests.

Change-Id: I26fd06d90ae6bf5fc5aed24bc2ac826ad69eee31
Reviewed-on: https://gem5-review.googlesource.com/11182
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>