sysdev-accessing-hardware-stm32: fix version for dtsi file

As the latest version is no longer relevant.

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>

labs/sysdev-accessing-hardware-stm32/sysdev-accessing-hardware-stm32.tex

@@ -289,7 +289,7 @@ \subsection{Customizing the Device Tree}
 
 Fortunately, I2C5 is already defined in the one of the DTS includes
 used by the Device Tree for our board. In our case, that's in
-\kfile{arch/arm/boot/dts/stm32mp151.dtsi}. Look by yourself in this
+\kfileversion{arch/arm/boot/dts/stm32mp151.dtsi}{6.1}. Look by yourself in this
 file, and you will find its definition, but with \code{status =
 "disabled";}. This means that this I2C controller is not enabled yet,
 and it's up to boards using it to do so.