package/qt6base: remove $(TARGET_DIR)/usr/mkspecs in target-finalize

qt6base installs things in /usr/mkspecs, but also the soon to be added
qt6core5compat, and the existing package qwt as well.

So let's move the removal of /usr/mkspecs in target-finalize, where we
already remove lots of development-related directories, using a
target-finalize hook in the qt6base package.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[yann.morin.1998@free.fr: make it a qt6base target-finalize hook]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/qt6/qt6base/qt6base.mk

@@ -366,5 +366,10 @@ else
 QT6BASE_CONF_OPTS += -DFEATURE_zstd=OFF
 endif
 
+define QT6BASE_RM_USR_MKSPECS
+	$(Q)rm -rf $(TARGET_DIR)/usr/mkspecs
+endef
+QT6BASE_TARGET_FINALIZE_HOOKS += QT6BASE_RM_USR_MKSPECS
+
 $(eval $(cmake-package))
 $(eval $(host-cmake-package))

package/qwt/qwt.mk

@@ -58,7 +58,6 @@ endef
 
 define QWT_INSTALL_TARGET_CMDS
 	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D) install INSTALL_ROOT=$(TARGET_DIR)
-	rm -Rf $(TARGET_DIR)/usr/mkspecs
 endef
 
 $(eval $(qmake-package))