PurleyOpenBoardPkg : LinuxBoot Improvements

LinuxBoot : Remove separate initrd file. Linux Binaries build with an
Integrated Initrd
Synced edk2-platforms\Platform\Intel\PurleyOpenBoardPkg\Override\Platform\
Intel\MinPlatformPkg\Bds with the latest edk2-platforms\Platform\Intel\
MinPlatformPkg\Bds
Applied and moved earlier overrides done in DxePlatformBootManagerLib to
BoardBdsHookLib

Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Harikrishna Doppalapudi <harikrishnad@ami.com>
Cc: Manish Jha <manishj@ami.com>
Cc: Manickavasakam Karpagavinayagam <manickavasakamk@ami.com>
Cc: Zachary Bobroff <zacharyb@ami.com>
Signed-off-by: Manickavasakam Karpagavinayagam <manickavasakamk@ami.com>
Signed-off-by: Isaac Oram <isaac.w.oram@intel.com>
Reviewed-by: Isaac Oram <isaac.w.oram@intel.com>