parisc: Raise minimal GCC version

64-bit targets need the __int128 type, which for pa-risc means raising
the minimum gcc version to 11.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20230602143912.GI620383%40hirez.programming.kicks-ass.net