Remove reference to f303 reference manual

Svein Kristian Rougseth · eldruin · commit dd0ab1c5049b · 2022-07-25T09:46:52.000+02:00
F303 is wrong, but where this can be found in the reference manual
differs from product line to product line within the f7-series, so I
suggest removing this note from the module doc
diff --git a/src/rtc.rs b/src/rtc.rs
@@ -1,4 +1,4 @@
-//! Interface to the real time clock. See STM32F303 reference manual, section 27.
+//! Interface to the real time clock.
 //! For more details, see
 //! [ST AN4759](https://www.st.com/resource/en/application_note/an4759-using-the-hardware-realtime-clock-rtc-and-the-tamper-management-unit-tamp-with-stm32-microcontrollers-stmicroelectronics.pdf)
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-//! Interface to the real time clock. See STM32F303 reference manual, section 27.`
	`1`	`+//! Interface to the real time clock.`
`2`	`2`	`//! For more details, see`
`3`	`3`	`//! [ST AN4759](https://www.st.com/resource/en/application_note/an4759-using-the-hardware-realtime-clock-rtc-and-the-tamper-management-unit-tamp-with-stm32-microcontrollers-stmicroelectronics.pdf)`
`4`	`4`