libflashprog: Name flashprog-wp doxygen group "Write Protection"

Change-Id: I6d9bf3aa0ff60afbe115369e01a007434ae25502
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/513
diff --git a/libflashprog.c b/libflashprog.c
index 7e2cea1..6cdb135 100644
--- a/libflashprog.c
+++ b/libflashprog.c
@@ -560,7 +560,7 @@
 
 
 /**
- * @defgroup flashprog-wp
+ * @defgroup flashprog-wp Write Protection
  * @{
  */