powerpc: Remove some unnecessary uses of _GLOBAL() and _STATIC()

There is no need to create a function descriptor for functions
called locally out of assembly.

Signed-off-by: Anton Blanchard <anton@samba.org>

diff --cc arch/powerpc/kernel/exceptions-64e.S
Simple merge

diff --cc arch/powerpc/kernel/exceptions-64s.S
Simple merge

diff --cc arch/powerpc/kernel/head_64.S
Simple merge