UPSTREAM: arm64: introduce mov_q macro to move a constant into a 64-bit register

Implement a macro mov_q that can be used to move an immediate constant
into a 64-bit register, using between 2 and 4 movz/movk instructions
(depending on the operand)

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Change-Id: I7e6b684e46cad5df79e6b8bc28d72b9e37daedd6
(cherry picked from commit 30b5ba5c)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>