OvmfPkg X64: Convert 24KB from uncompressed to compressed storage

OvmfPkg X64: Convert 24KB from uncompressed to compressed storage

Since we no longer require flash tables to be stored uncompressed
in the flash image, we can now give extra space to the main/compressed
storage area.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14718 6f19259b-4bc3-4df7-8a09-765794883524