qemu security update

[15:3.1.0-5.el7]

• Only enable the halt poll control MSR if it is supported by the host (Mark
  Kanda) [Orabug: 29946722]
  [15:3.1.0-4.el7]
• kvm: i386: halt poll control MSR support (Marcelo Tosatti) [Orabug: 29933278]
• Document CVEs as fixed: CVE-2017-9524, CVE-2017-6058, CVE-2017-5931 (Mark Kanda) [Orabug: 29886908] {CVE-2017-5931} {CVE-2017-6058} {CVE-2017-9524}
• pvrdma: release device resources in case of an error (Prasad J Pandit) [Orabug: 29056678] {CVE-2018-20123}
• qxl: check release info object (Prasad J Pandit) [Orabug: 29886906] {CVE-2019-12155}
• target/i386: add MDS-NO feature (Paolo Bonzini) [Orabug: 29820428] {CVE-2018-12126} {CVE-2018-12127} {CVE-2018-12130} {CVE-2019-11091}
• docs: recommend use of md-clear feature on all Intel CPUs (Daniel P. Berrange) [Orabug: 29820428] {CVE-2018-12126} {CVE-2018-12127} {CVE-2018-12130} {CVE-2019-11091}
• target/i386: define md-clear bit (Paolo Bonzini) [Orabug: 29820428] {CVE-2018-12126} {CVE-2018-12127} {CVE-2018-12130} {CVE-2019-11091}
• pvh: block migration if booting using PVH (Liam Merwick) [Orabug: 29796676]
• hw/i386/pc: run the multiboot loader before the PVH loader (Stefano Garzarella) [Orabug: 29796676]
• optionrom/pvh: load initrd from fw_cfg (Stefano Garzarella) [Orabug: 29796676]
• hw/i386/pc: use PVH option rom (Stefano Garzarella) [Orabug: 29796676]
• qemu.spec: add pvh.bin to %files (Liam Merwick) [Orabug: 29796676]
• optionrom: add new PVH option rom (Stefano Garzarella) [Orabug: 29796676]
• linuxboot_dma: move common functions in a new header (Stefano Garzarella) [Orabug: 29796676]
• linuxboot_dma: remove duplicate definitions of FW_CFG (Stefano Garzarella) [Orabug: 29796676]
• pvh: load initrd and expose it through fw_cfg (Stefano Garzarella) [Orabug: 29796676]
• pvh: Boot uncompressed kernel using direct boot ABI (Liam Merwick) [Orabug: 29796676]
• pvh: Add x86/HVM direct boot ABI header file (Liam Merwick) [Orabug: 29796676]
• elf-ops.h: Add get_elf_note_type() (Liam Merwick) [Orabug: 29796676]
• elf: Add optional function ptr to load_elf() to parse ELF notes (Liam Merwick) [Orabug: 29796676]