powerpc: Move patch sites out of asm-prototypes.h

The definitions for the patch sites etc. don't belong in
asm-prototypes.h, they are not EXPORT'ed asm symbols.

Move them into sections.h which is traditionally used for asm symbols.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220818050659.187181-1-mpe@ellerman.id.au