cmake: remove BUILD type in function description.

Build type was removed in 763a49f but
the function description was not updated accordingly.

Remove build type from the function description.

Add board qualifier as that is missing.

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>

Author: tejlmand

cmake/modules/extensions.cmake

@@ -1587,8 +1587,8 @@ function(pow2round n)
   set(${n} ${${n}} PARENT_SCOPE)
 endfunction()
 
-# Function to create a build string based on BOARD, BOARD_REVISION, and BUILD
-# type.
+# Function to create a build string based on BOARD, BOARD_REVISION, and
+# BOARD_QUALIFIER.
 #
 # This is a common function to ensure that build strings are always created
 # in a uniform way.