base: Create a SConscript for the loader subdirectory.

These files had been handled in base/SConscript, but there are enough of
them that they deserve their own.

Change-Id: I0c4166d8ff3c761c25940d2af5d7f0a9a6c874fa
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33898
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2 files changed