gem5/gem5-m5ops: initial recipe

m5ops provide pseudo-instructions to trigger gem5 functionality.
m5 utility provides a CLI for m5ops.
libm5.a provides a C library for m5ops.

Change-Id: Ib06dcb539648407522e31aeb1ed392fb5232675e
Signed-off-by: Adrian Herrera <adrian.herrera@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>