"make check-functional" fails on a build with only the hppa targets

If you configure a build like this:

'../../configure' '--target-list=hppa-linux-user,hppa-softmmu' '--enable-debug' '--cc=ccache gcc' '--disable-docs' '--disable-tools' 

then "make check-functional" fails like this:

$ make -C build/hppa check-functional
make: Entering directory '/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/hppa'

[0/1] Running external command precache-functional (wrapped by meson to set env)
make[1]: Entering directory '/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/hppa'
make[1]: *** No rule to make target 'check-func'. Stop.
make[1]: Leaving directory '/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/hppa'
make: *** [/home/petmay01/linaro/qemu-from-laptop/qemu/tests/Makefile.include:114: check-functional] Error 2
make: Leaving directory '/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/hppa'

My guess is that this is because hppa happens to only have "quick" functional tests, and no "thorough" ones. However, we shouldn't fail to run the top-level "check-functional" target in this situation.