lib: Mark memcpy() and memmove() as relocation code

lib: Mark memcpy() and memmove() as relocation code

Mark these functions as needed by relocation. These functions are used
to copy data while relocating the next-phase image.

Drop the 'safe' versions from SPL as they are not needed. Change the
static array to a local one, to avoid link errors when trying to access
the data.

Signed-off-by: Simon Glass <sjg@chromium.org>