arm64: jump_label: mark arguments as const to satisfy asm constraints

Inspired by x86 commit 864b4355("x86/jump_label: Mark arguments as
const to satisfy asm constraints"), mark arch_static_branch()'s and
arch_static_branch_jump()'s arguments as const to satisfy asm
constraints. And Steven in [1] also pointed out that "The "i"
constraint needs to be a constant."

Tested with building a simple external kernel module with "O0".

[1]https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/



Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221006075542.2658-2-jszhang@kernel.org


Signed-off-by: Will Deacon <will@kernel.org>