[OE-core] [PATCH] cmake: Try and improve cleaning of builds when B==S

[Richard Purdie]

Currently if B==S for a cmake recipe, the build will not reconfigure. This patch adds 
code to remove the generated cmake files, meaning cmake will then be forced to regenerate
them. This forces cmake to see configuration changes it may not otherwise see.

Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

diff --git a/meta/classes/cmake.bbclass b/meta/classes/cmake.bbclass
index 995ddf1..10f8f98 100644
--- a/meta/classes/cmake.bbclass
+++ b/meta/classes/cmake.bbclass
@@ -79,6 +79,8 @@ cmake_do_configure() {
 		rm -rf ${B}
 		mkdir -p ${B}
 		cd ${B}
+	else
+		find ${B} -name CMakeFiles -or -name Makefile -or -name cmake_install.cmake -or -name CMakeCache.txt -delete	
 	fi
 
 	# Just like autotools cmake can use a site file to cache result that need generated binaries to run