arm/static-shmem.h: drop inclusion of asm/setup.h

arm/static-shmem.h: drop inclusion of asm/setup.h

Nothing is dependent from asm/setup.h in asm/static-shmem.h so inclusion of
asm/setup.h is droped.

After this drop the following compilation error related to impicit declaration
of the following functions device_tree_get_reg and map_device_irqs_to_domain,
device_tree_get_u32 occur during compilation of dom0less-build.c ( as they are
declared in asm/setup.h ).

Add inclusion of <asm/setup.h> in dt-overlay.c as it is using handle_device()
declared in <asm/setup.h>.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>