learning-gem5: Fix missing misc.hh in hello_object.cc

misc.hh has been renamed in
commit 1088f0c4ac3999fc3c363cc51daef4cfb360a2bd

Change-Id: Ic4f8c6423e6a5466f8d924e793a24f62bb4eca9c
Reviewed-on: https://gem5-review.googlesource.com/6361
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
1 file changed