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/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
index cc3a54f..b0c656d 100644
--- a/drivers/spi/cadence_qspi.c
+++ b/drivers/spi/cadence_qspi.c
@@ -18,12 +18,11 @@
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/sizes.h>
+#include <linux/time.h>
 #include <zynqmp_firmware.h>
 #include "cadence_qspi.h"
 #include <dt-bindings/power/xlnx-versal-power.h>
 
-#define NSEC_PER_SEC			1000000000L
-
 #define CQSPI_STIG_READ			0
 #define CQSPI_STIG_WRITE		1
 #define CQSPI_READ			2