arch: Minor cleanup of imports in isa_parser.py.

The with statement and print function are no longer in the future, and
the "inspect" module is not used. Also alphabetize the imports.

Change-Id: I35f2b7b0f7495cb9ca79d2cbe05f020560ec3593
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35280
Reviewed-by: Steve Reinhardt <stever@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/isa_parser/isa_parser.py

@@ -37,11 +37,10 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-from __future__ import with_statement, print_function
 import os
-import sys
 import re
-import inspect, traceback
+import sys
+import traceback
 # get type names
 from types import *