hexagon: mm: mark paging_init() as static

hexagon: mm: mark paging_init() as static

Clang warns:

  arch/hexagon/mm/init.c:89:13: warning: no previous prototype for function 'paging_init' [-Wmissing-prototypes]
     89 | void __init paging_init(void)
        |             ^
  arch/hexagon/mm/init.c:89:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     89 | void __init paging_init(void)
        | ^
        | static

This function is only used within this translation unit, so mark it static
as suggested.

Link: https://lkml.kernel.org/r/20231130-hexagon-missing-prototypes-v1-2-5c34714afe9e@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>