gem5: Add MSI and GIC_v2m build support to arm architecture Modify mach-vexpress/Kconfig and include/asm/Kbuild to build in MSI support for armv7 so we can use the GIC_V2M with PCI devices that support MSI and MSI-X. Signed-off-by: Geoffrey Blake <Geoffrey.Blake@arm.com> Change-Id: I0858eeb6ea713cb5725d24524dc522dfecd56e45 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> [Ported to 4.9] Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>