ARM/ARM64: arch_timer: add macros for bits in control register

ARM/ARM64: arch_timer: add macros for bits in control register

Add macros to describe the bitfields in the ARM architected timer
control register to make code easy to understand.

Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
(cherry picked from commit 28061758dc83df445a05af347b5ce55ccd968c03)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
	arch/arm/include/asm/arch_timer.h