Commit 63ab25eb (kgdbts: unify/generalize gdb breakpoint adjustment)
introduced a compile regression on sparc.

kgdbts.c: In function 'check_and_rewind_pc':
kgdbts.c:307: error: implicit declaration of function 'instruction_pointer_set'

Simply add the correct macro definition for instruction pointer on the
Sparc architecture.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>