[PARISC] Compat signal fixes for 64-bit parisc

In copy_siginfo_from_user32:
Use compat_uptr_t. Use compat_ptr().

In copy_siginfo_to_user32:
Use compat_int_t. Use ptr_to_compat().

The sigevent_t structure has a 64-bit si_ptr field
that when copied to a 32-bit si_ptr will copy the wrong
word. For the compat copy use the si_int field instead.

Signed-off-by: Carlos O'Donell <carlos@systemhalted.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>