linux.ui: Add CPU entries under Resources View aggregated IRQ entries

linux.ui: Add CPU entries under Resources View aggregated IRQ entries

This adds CPU entries under the root IRQ entries in the resource view.

They look like this at the moment.

SOFT_IRQ 1 Timer: ------------[rrrrrrr|xx|xxxxx|xx]
......CPU 0     : -------------[rrrrrrrrr|xxxxx]
......CPU 1     : ------------[rrrrrrr|xx]
......CPU 2     : ---------------------[rrrrrrr|xx]

This implements the solution suggested in bug 381497

Change-Id: Ie0c9e9e505d4fb66a39579a0891620373e4d1e00
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/67453
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Hudson CI