arm64: lib: Use modern annotations for assembly functions

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the library code to the
new macros.

Signed-off-by: Mark Brown <broonie@kernel.org>
[will: Use SYM_FUNC_START_WEAK_PI]
Signed-off-by: Will Deacon <will@kernel.org>