OvmfPkg: Add support for qemu's -kernel parameter

If QEMU's -kernel parameter was used, then download the
kernel from the FwCfg interface, and launch it.  (See -kernel,
-initrd, -append) The application uses the LoadLinuxLib to boot
the kernel image.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13923 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/Library/PlatformBdsLib/BdsPlatform.h

@@ -295,4 +295,15 @@ PlatformBdsEnterFrontPage (
   IN BOOLEAN                ConnectAllHappened
   );
 
+/**
+  Loads and boots UEFI Linux via the FwCfg interface.
+
+  @retval    EFI_NOT_FOUND - The Linux kernel was not found
+
+**/
+EFI_STATUS
+TryRunningQemuKernel (
+  VOID
+  );
+
 #endif // _PLATFORM_SPECIFIC_BDS_PLATFORM_H_