[PARISC] Specify level to fix binutils level promotion bug

fixup.S needs to specify .level and use correct LDREG macro.
New binutils has a bug where it doesn't "promote" from PA1.0 to PA1.1
correctly when using ",s" completer.

remove use of __LP64__ in assembly.h and add some white space.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>