scons: Remove the extra_deps option from the helper function make_obj.
scons: Remove the extra_deps option from the helper function make_obj.

This had only one use, and made the function more complicated than it
needed to be.

Change-Id: I22147a0c1239b457c577a6a24b423065e539833b
Reviewed-on: https://gem5-review.googlesource.com/5983
Reviewed-by: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Reviewed-by: Nikos Nikoleris <b6a1b3cd9d36c44e9eeb16bc870df3cb2a0cf469@arm.com>
Maintainer: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>

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