drv_hrt: Fix hrt_abstime literal argument names

The user-defined literals for milli- and microseconds
should have argument names matching their units. The
current argument names 'seconds' is probably an oversight.

src/drivers/drv_hrt.h

@@ -225,14 +225,14 @@ constexpr hrt_abstime operator "" _s(unsigned long long seconds)
 	return hrt_abstime(seconds * 1000000ULL);
 }
 
-constexpr hrt_abstime operator "" _ms(unsigned long long seconds)
+constexpr hrt_abstime operator "" _ms(unsigned long long milliseconds)
 {
-	return hrt_abstime(seconds * 1000ULL);
+	return hrt_abstime(milliseconds * 1000ULL);
 }
 
-constexpr hrt_abstime operator "" _us(unsigned long long seconds)
+constexpr hrt_abstime operator "" _us(unsigned long long microseconds)
 {
-	return hrt_abstime(seconds);
+	return hrt_abstime(microseconds);
 }
 
 } /* namespace time_literals */