Pull ia64-clocksource into release branch

Documentation/kernel-parameters.txt

Documentation/time_interpolators.txt

arch/ia64/Kconfig

arch/ia64/configs/bigsur_defconfig

arch/ia64/configs/gensparse_defconfig

arch/ia64/configs/sim_defconfig

arch/ia64/configs/sn2_defconfig

arch/ia64/configs/tiger_defconfig

arch/ia64/configs/zx1_defconfig

arch/ia64/defconfig

arch/ia64/kernel/asm-offsets.c

arch/ia64/kernel/cyclone.c

arch/ia64/kernel/fsys.S

arch/ia64/kernel/fsyscall_gtod_data.h

arch/ia64/kernel/time.c

arch/ia64/sn/kernel/sn2/timer.c

drivers/acpi/processor_idle.c

drivers/char/hpet.c

include/linux/clocksource.h

include/linux/timex.h