timestamps: COLLECT_TIMESTAMPS is mostly optional

It is a user-visible option and enabled by default for ARCH_X86,
some consider it as debugging aid only. Therefore platform design
should not depend on it.

It must remain selected with CHROMEOS and boards are allowed
to explicitly select it as well.

For siemens/mc_bdx1,mc_aplX boot time will be increased due
the use of get_us_since_boot() with COLLECT_TIMESTAMPS=n.
When unable to determine if N seconds has elapsed from boot,
this turns into a delay of N seconds.

Change-Id: I6ee4195d266440143344781d39db9578cd8bdcb3
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36527
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/soc/intel/apollolake/Kconfig

@@ -40,7 +40,6 @@ config CPU_SPECIFIC_OPTIONS
 	# Misc options
 	select C_ENVIRONMENT_BOOTBLOCK
 	select CACHE_MRC_SETTINGS
-	select COLLECT_TIMESTAMPS
 	select COMMON_FADT
 	select FSP_PLATFORM_MEMORY_SETTINGS_VERSIONS
 	select GENERIC_GPIO_LIB