vulkan: Add VK_EXT_calibrated_timestamps extension (radv and anv) [v5]

vulkan: Add VK_EXT_calibrated_timestamps extension (radv and anv) [v5]

Offers three clocks, device, clock monotonic and clock monotonic
raw. Could use some kernel support to reduce the deviation between
clock values.

v2:
	Ensure deviation is at least as big as the GPU time interval.

v3:
	Set device->lost when returning DEVICE_LOST.
	Use MAX2 and DIV_ROUND_UP instead of open coding these.
	Delete spurious TIMESTAMP in radv version.

	Suggested-by: Jason Ekstrand <jason@jlekstrand.net>
	Suggested-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
v4:
	Add anv_gem_reg_read to anv_gem_stubs.c

	Suggested-by: Jason Ekstrand <jason@jlekstrand.net>
v5:
	Adjust maxDeviation computation to max(sampled_clock_period) +
	sample_interval.

	Suggested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
	Suggested-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>