scons: Remove SWIG support
scons: Remove SWIG support

Remove remaining SWIG support from the build infrastructure.

Change-Id: I7549cd0f952ca3a51481918eefef3a29f03af359
Signed-off-by: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Reviewed-by: Andreas Hansson <b81e6ed0c244a09b5b4a6914f14e521a5fdcb1a3@arm.com>
Reviewed-by: Curtis Dunham <14490907fdc9c150c92157b82121c81003bbdc71@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2920
Reviewed-by: Jason Lowe-Power <68c46a606457643eab92053c1c05574abb26f861@lowepower.com>
Reviewed-by: Tony Gutierrez <fe4627c83134668039628e34eb0e4dda45a5da5e@amd.com>

gedare/gem5,rallylee/gem5,powerjg/gem5-ci-test,TUD-OS/gem5-dtu,Weil0ng/gem5,powerjg/gem5-ci-test,rallylee/gem5,Weil0ng/gem5,Weil0ng/gem5,rallylee/gem5,sobercoder/gem5,TUD-OS/gem5-dtu,powerjg/gem5-ci-test,gem5/gem5,sobercoder/gem5,Weil0ng/gem5,TUD-OS/gem5-dtu,powerjg/gem5-ci-test,gem5/gem5,Weil0ng/gem5,Weil0ng/gem5,rallylee/gem5,gem5/gem5,sobercoder/gem5,rallylee/gem5,rallylee/gem5,TUD-OS/gem5-dtu,gedare/gem5,sobercoder/gem5,gedare/gem5,gem5/gem5,powerjg/gem5-ci-test,gedare/gem5,gedare/gem5,TUD-OS/gem5-dtu,rallylee/gem5,sobercoder/gem5,gedare/gem5,sobercoder/gem5,gedare/gem5,powerjg/gem5-ci-test,powerjg/gem5-ci-test,TUD-OS/gem5-dtu,Weil0ng/gem5,gem5/gem5,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,sobercoder/gem5