kconfig: Qt5: tell the user which packages are required

Along with saying "Please install Qt5 ...", tell exactly which
parts of Qt5 are needed. This is useful when parts of Qt5 are
installed but some of the required pieces are missing, and it
eliminates the need for the user to find the shell script and
the line in it that provide that information.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>