NANOSECONDS_PER_SECOND is often used in operations with get_ns(), which
currently returns a u64.

Therefore, define a new NANOSECONDS_PER_SECOND binding is with u64 type
to eliminate unnecessary type conversions (from u32 to u64).

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 rust/qemu-api/src/timer.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rust/qemu-api/src/timer.rs b/rust/qemu-api/src/timer.rs
index f0b04ef95d7e..e769f8bc910d 100644
--- a/rust/qemu-api/src/timer.rs
+++ b/rust/qemu-api/src/timer.rs
@@ -121,3 +121,5 @@ pub fn get_ns(&self) -> u64 {
 pub const CLOCK_VIRTUAL: ClockType = ClockType {
     id: QEMUClockType::QEMU_CLOCK_VIRTUAL,
 };
+
+pub const NANOSECONDS_PER_SECOND: u64 = 1000000000;
-- 
2.34.1