ext: Remove non-source files from fputils

ext: Remove non-source files from fputils

Remove the autoconf-based build system and GNU-style information files
from fputils. After this change, we only keep the files we will need
to integrate into gem5's main source tree.

Change-Id: I2ddf1d07d9cb51bcd91fc63f1ae43c7f46129933
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22163
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <jason@lowepower.com>