OvmfPkg: AcpiTables: serialize control methods that create named objects

OvmfPkg: AcpiTables: serialize control methods that create named objects

Bruce Cran reported the following issue:

  With iasl version 20150410-64 building OvmfX64 (using OvmfPkg/build.sh
  -a X64 -t GCC49 -b RELEASE) results in a couple of warnings about
  methods that should be serialized:

  .../OvmfPkg/AcpiTables/AcpiTables/OUTPUT/./Dsdt.iiii
  95:       Method (_CRS, 0) {
  Remark   2120 - Control Method should be made Serialized ^  (due to
  creation of named objects within)

  .../OvmfPkg/AcpiTables/AcpiTables/OUTPUT/./Dsdt.iiii
  235:         Method (PCRS, 1, NotSerialized) {
  Remark   2120 - Control Method should be made Serialized ^  (due to
  creation of named objects within)

The ACPI 6.0 spec justifies the above warnings in "19.6.82 Method (Declare
Control Method)":

  [...] The serialize rule can be used to prevent reentering of a method.
  This is especially useful if the method creates namespace objects.
  Without the serialize rule, the reentering of a method will fail when it
  attempts to create the same namespace object. [...]

Cc: Bruce Cran <bruce@cran.org.uk>
Reported-by: Bruce Cran <bruce@cran.org.uk>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18392 6f19259b-4bc3-4df7-8a09-765794883524