ARM: import arm-smccc code from Linux 4.11-rc6

Imports ARM SMC Calling Convention code from Linux 4.11-rc6.
The files have been copied as follows:

[Linux]                           [U-Boot]
arch/arm/kernel/smccc-call.S   -> arch/arm/cpu/armv7/smccc-call.S
arch/arm64/kernel/smccc-call.S -> arch/arm/cpu/armv8/smccc-call.S
arch/arm/include/asm/opcodes*  -> arch/arm/include/asm/opcodes*
include/linux/arm-smccc.h      -> include/linux/arm-smccc.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>