parisc: Pass endianness info to sparse

parisc is big-endian only but sparse assumes the same endianness as the
building machine.
This is problematic for code which expect __BYTE_ORDER__ being correctly
predefined by the compiler which sparse can then pre-process differently
from what gcc would.

Fix this by letting sparse know about the architecture endianness.

To: James Bottomley <jejb@parisc-linux.org>
To: Helge Deller <deller@gmx.de>
CC: linux-parisc@vger.kernel.org
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>