sh: Fix up asm-generic/ptrace.h fallout.

There was an ordering issue with regards to instruction_pointer() being
used in profile_pc() prior to the asm-generic/ptrace.h include, which
subsequently provided the instruction_pointer() definition. In the
interest of simplicity we simply open-code the regs->pc deref for the
profile_pc() definition instead.

The FP functions were also broken due to a lack of a common regs->fp,
so provide a common GET_FP() that is safe for both architectures in order
to fix up the frame pointer helpers too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>