systemc: Fix a function which was broken during style fixes.

Some brackets were misapplied while correcting the style of the TLM
header files.

Change-Id: I4e26d0316ca2545a5f26ad5fef0e986e42a1895b
Reviewed-on: https://gem5-review.googlesource.com/c/15455
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

systemc: Fix style issues in the TLM header files.

Change-Id: Id12ffb9b56b3887afcf30120f81ce5eb75a5987b
Reviewed-on: https://gem5-review.googlesource.com/c/15057
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

systemc: Initial import of TLM headers from Accellera.

These headers will need to be cleaned up and have some Accellera
specific quirks ironed out of them, but I'll do that in a later change
to make it clear what those changes are.

Change-Id: Ia4e08633ab552b4c616c66c9b7e2bbd78ebfe7b9
Reviewed-on: https://gem5-review.googlesource.com/c/15055
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>