tests: cross-compiling hello binaries for hello_se tests.

tests: cross-compiling hello binaries for hello_se tests.

Some of the hello_se tests fail due to different syntax of the string
for different isas. This patch adds makefiles for cross-compiling the
hello.c file located at tests/test-progs/hello/src/.

Change-Id: I8ccfc0487020df9da722a97e57310db2d2e8882c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28528
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>