riscv: fix warning in arch/riscv/include/asm/module.h

[ Upstream commit 0138ebb90c633f76bc71617f8f23635ce41c84fd ]

Fixes warning: 'struct module' declared inside parameter list will not be
visible outside of this definition or declaration

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>