pwm: lpc18xx-sct: Fix a comment to match code

lpc18xx_pwm_probe() only ensures clk_rate <= NSEC_PER_SEC, the following
reasoning is right even under this slightly lesser condition.

Fixes: 8933d30 ("pwm: lpc18xx: Fix period handling")
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://lore.kernel.org/r/20221108153013.132514-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-lpc18xx-sct.c

@@ -175,7 +175,7 @@ static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
 	u32 val;
 
 	/*
-	 * With clk_rate < NSEC_PER_SEC this cannot overflow.
+	 * With clk_rate <= NSEC_PER_SEC this cannot overflow.
 	 * With duty_ns <= period_ns < max_period_ns this also fits into an u32.
 	 */
 	val = mul_u64_u64_div_u64(duty_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);