A couple of functions are declared in arch/arm/mm/mmu.c rather than in a header,
which causes W=1 build warnings:

arch/arm/mm/init.c:97:13: error: no previous prototype for 'setup_dma_zone' [-Werror=missing-prototypes]
arch/arm/mm/mmu.c:118:13: error: no previous prototype for 'init_default_cache_policy' [-Werror=missing-prototypes]
arch/arm/mm/mmu.c:1195:13: error: no previous prototype for 'adjust_lowmem_bounds' [-Werror=missing-prototypes]
arch/arm/mm/mmu.c:1761:13: error: no previous prototype for 'paging_init' [-Werror=missing-prototypes]
arch/arm/mm/mmu.c:1794:13: error: no previous prototype for 'early_mm_init' [-Werror=missing-prototypes]

Move the declaratsion to asm/setup.h so they can be seen by the compiler
while building the definition.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>