qemu: upgrade to 2.1

QEMU 2.1 comes with fixes and improvements.
See http://wiki.qemu.org/ChangeLog/2.1 for details.
- Added config for quorum support, depending on gnutls.
- pcie_better_hotplug_support.patch removed,
integrated upstream.
- Qemu-Arm-versatilepb-Add-memory-size-checking.patch updated
to 2.1 source code.
- no-strip.patch removed, no longer necessary due to code changes.

Signed-off-by: Cristian Iorga <cristian.iorga@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>