devel/qt5-qdoc: fix CMake Config file for doctools

We patch Qt to install into $LOCALBASE/lib/qt5, but the CMake
bits of Qt go into $LOCALBASE; this mismatch of installation-
prefixes means that the CMake Config files are generated with
an incorrect number of "../" components, and end up looking in
the wrong prefix. Symptom is this:

  The package "Qt5DocTools" references the file
     "/usr/lib/qt5/bin/qdoc"

The logic to use the correct path is there, but not selected
when writing out the Config file. Delete all the ones we don't
want, rather than letting qmake / whatever text-substitution tool
is in the build do it.

Suggested by:	tcberner

devel/qt5-qdoc/Makefile

 PORTNAME=	qdoc
 PORTVERSION=	${QT5_VERSION}${QT5_KDE_PATCH}
+PORTREVISION=	1
 CATEGORIES=	devel textproc
 PKGNAMEPREFIX=	qt5-
 

devel/qt5-qdoc/files/patch-src_qdoc_Qt5DocToolsConfig.cmake.in

+--- src/qdoc/Qt5DocToolsConfig.cmake.in.orig	2022-02-06 16:38:55 UTC
++++ src/qdoc/Qt5DocToolsConfig.cmake.in
+@@ -2,29 +2,7 @@ if (CMAKE_VERSION VERSION_LESS 2.8.3)
+     message(FATAL_ERROR \"Qt 5 requires at least CMake version 2.8.3\")
+ endif()
+ 
+-!!IF !isEmpty(CMAKE_USR_MOVE_WORKAROUND)
+-!!IF !isEmpty(CMAKE_LIB_DIR_IS_ABSOLUTE)
+ set(_qt5_qdoctools_install_prefix \"$$[QT_INSTALL_PREFIX]\")
+-!!ELSE
+-get_filename_component(_IMPORT_PREFIX \"${CMAKE_CURRENT_LIST_FILE}\" PATH)
+-# Use original install prefix when loaded through a
+-# cross-prefix symbolic link such as /lib -> /usr/lib.
+-get_filename_component(_realCurr \"${_IMPORT_PREFIX}\" REALPATH)
+-get_filename_component(_realOrig \"$$CMAKE_INSTALL_LIBS_DIR/cmake/Qt5DocTools\" REALPATH)
+-if(_realCurr STREQUAL _realOrig)
+-    get_filename_component(_qt5_qdoctools_install_prefix \"$$CMAKE_INSTALL_LIBS_DIR/$${CMAKE_RELATIVE_INSTALL_LIBS_DIR}\" ABSOLUTE)
+-else()
+-    get_filename_component(_qt5_qdoctools_install_prefix \"${CMAKE_CURRENT_LIST_DIR}/$${CMAKE_RELATIVE_INSTALL_DIR}\" ABSOLUTE)
+-endif()
+-unset(_realOrig)
+-unset(_realCurr)
+-unset(_IMPORT_PREFIX)
+-!!ENDIF
+-!!ELIF isEmpty(CMAKE_LIB_DIR_IS_ABSOLUTE)
+-get_filename_component(_qt5_qdoctools_install_prefix \"${CMAKE_CURRENT_LIST_DIR}/$${CMAKE_RELATIVE_INSTALL_DIR}\" ABSOLUTE)
+-!!ELSE
+-set(_qt5_qdoctools_install_prefix \"$$[QT_INSTALL_PREFIX]\")
+-!!ENDIF
+ 
+ macro(_qt5_DocTools_check_file_exists file)
+     if(NOT EXISTS \"${file}\" )