units: don't install pcrphase-related units without gnu-efi

units: don't install pcrphase-related units without gnu-efi

since we don't have systemd-pcrphase built anyway, which breaks the tests:

...
I: Attempting to install /usr/lib/systemd/systemd-networkd-wait-online (based on unit file reference)
I: Attempting to install /usr/lib/systemd/systemd-network-generator (based on unit file reference)
I: Attempting to install /usr/lib/systemd/systemd-oomd (based on unit file reference)
I: Attempting to install /usr/lib/systemd/systemd-pcrphase (based on unit file reference)
W: Failed to install '/usr/lib/systemd/systemd-pcrphase'
make: *** [Makefile:4: setup] Error 1
make: Leaving directory '/root/systemd/test/TEST-01-BASIC'

Follow-up to 04959faa632272a8fc9cdac3121b2e4af721c1b6.