parisc: Use PA_ASM_LEVEL in boot code

commit bdca5d64ee92abeacd6dada0bc6f6f8e6350dd67 upstream.

The LEVEL define clashed with the DRBD code.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>