arch: Remove the stacktrace.hh switching header file.
arch: Remove the stacktrace.hh switching header file.

This is no longer used.

Change-Id: I1419b28d51ff603beb7d8ab89632ad7038c3057e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32215
Reviewed-by: Bobby R. Bruce <b9dba908ffb6c6d8ffe449cc88b3709c13c485c2@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Maintainer: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

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