parisc: Wrap assembler related defines inside __ASSEMBLY__

Building allmodconfig shows errors in the gpu/drm/msm snapdragon drivers,
because a COND() define is used there which conflicts with the COND() for
PA-RISC assembly.  Although the snapdragon driver isn't relevant for parisc, it
is nevertheless compiled when CONFIG_COMPILE_TEST is defined.

Move the COND() define and other PA-RISC mnemonics inside the #ifdef
__ASSEMBLY__ part to avoid this conflict.

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: kernel test robot <lkp@intel.com>