parisc: Drop alloc_hugepages and free_hugepages syscalls

The system calls alloc_hugepages() and free_hugepages() were introduced
in Linux 2.5.36 and removed again in 2.5.54. They were never implemented
on parisc, so let's drop them now.

Signed-off-by: Helge Deller <deller@gmx.de>