util: Update jni_gem5Op.c so it will compile again.

util: Update jni_gem5Op.c so it will compile again.

The header for the m5op entry points had moved. Also the names of the
entry points had been normalized to have a consistent structure. Neither
of those changes were ported to this file, making it no longer compile.

Change-Id: I890c0486bd19fe2692cce92983290e854dc87afa
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27211
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>