arm: Fix armv8 compilation error

Fix following compilation error when CONFIG_ARM64 is defined

Error: unknown or missing system register name at operand 2
-- `mrs x0,daifmsr daifset,#3'

Signed-off-by: Shaibal.Dutta <shaibal.dutta@broadcom.com>
Signed-off-by: Darwin Rambo <drambo@broadcom.com>
Reviewed-by: Darwin Rambo <drambo@broadcom.com>