package/flutter-pi: fix Raspberry typo

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/flutter-pi/Config.in

@@ -24,7 +24,7 @@ menuconfig BR2_PACKAGE_FLUTTER_PI
 	  Desktop & have X11 or Wayland load up; just boot into the
 	  command-line.
 
-	  Although flutter-pi is only tested on a Rasberry Pi 4
+	  Although flutter-pi is only tested on a Raspberry Pi 4
 	  2GB, it should work fine on other linux platforms supported
 	  by Flutter so long as there is support for KMS and DRI.