treewide: use linux/time.h for time conversion defines

Now that we have time conversion defines from in time.h there is no need
for each driver to define their own version.

Signed-off-by: Igor Prusov <ivprusov@salutedevices.com>
Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com> # tegra
Reviewed-by: Eugen Hristev <eugen.hristev@collabora.com> #at91
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org> #qcom geni
Reviewed-by: Stefan Bosch <stefan_b@posteo.net> #nanopi2
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/drivers/pwm/pwm-aspeed.c b/drivers/pwm/pwm-aspeed.c
index ba98641..b03472d 100644
--- a/drivers/pwm/pwm-aspeed.c
+++ b/drivers/pwm/pwm-aspeed.c
@@ -49,6 +49,7 @@
 #include <dm/device_compat.h>
 #include <linux/math64.h>
 #include <linux/bitfield.h>
+#include <linux/time.h>
 #include <asm/io.h>
 
 /* The channel number of Aspeed pwm controller */
@@ -77,8 +78,6 @@
 /* PWM fixed value */
 #define PWM_ASPEED_FIXED_PERIOD 0xff
 
-#define NSEC_PER_SEC			1000000000L
-
 struct aspeed_pwm_priv {
 	struct clk clk;
 	struct regmap *regmap;