clocksource/drivers/tcb_clksrc: Fix clock speed message

The clock speed displayed at boot in an information message was 500 kHz
too high compared to its real value. As the value is not used anywhere,
there is no functional impact.

Fix the rounding formula to display the correct value.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1515418139-23276-4-git-send-email-daniel.lezcano@linaro.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>