os.linux: Fix CPU state when Softirq is interrupted

os.linux: Fix CPU state when Softirq is interrupted

This patch makes the cpu the aggregate of the PROCESS, all SOFTIRQs
and all IRQs. The process now does a rigourous check of every state
in the CPU. This can be later replaced with a virtual or aggregate entry
if deemed necessary.

This patch fixes bug 481855.

Change-Id: I1fd368362daf269c12cc4f12f459c5a1e404e420
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/68002
Reviewed-by: Hudson CI