MdePkg: Fixed hang/reset in thunk code when building with GCC X64

MdePkg:  Fixed hang/reset in thunk code when building with GCC X64

Reverted changes of data areas from .long back to .space 4.  This was done
because the size of .long is based off of .int and may vary.  Using a fixed size
is required because these values are for patching code.  Also note that .space
will automatically initialize the data to zero.  Not initializing all values to
zero was causing the hang/reset.

Signed-off-by: geekboy15a
Reviewed-by: darylm503
Reviewed-by: jljusten
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12079 6f19259b-4bc3-4df7-8a09-765794883524