x86/tsc: Handle CLOCK_SOURCE_VALID_FOR_HRES correctly

x86/tsc: Handle CLOCK_SOURCE_VALID_FOR_HRES correctly

Unconditionally setting the CLOCK_SOURCE_VALID_FOR_HRES for the real TSC
clocksource is wrong as there is no guarantee that the early TSC was
validated for high resolution mode.

Set the flag only when the early TSC was validated as otherwise the
clocksource selection might enable high resolution mode with a TSC of
unknown quality and possibly no way to back out once it is discovered to be
unsuitable.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260123231521.790598171@kernel.org