parisc: Increase size of gcc stack frame check

parisc uses much bigger frames than other architectures, so increase the
stack frame check value to avoid compiler warnings.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Helge Deller <deller@gmx.de>