powerpc/64s/exception: Remove the SPR saving patch code macros

These are used infrequently enough they don't provide much help, so
inline them.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-15-npiggin@gmail.com