sdbus-c++: Fix ptest packaging
sdbus-c++: Fix ptest packaging

Define builtin PTEST_PATH
Delete the systemd test fragment if ptest is not enabled
Fixes
NOTE: Executing Tasks
ERROR: sdbus-c++-0.8.1-r0 do_package: QA Issue: sdbus-c++: Files/directories were installed but not shipped in any package:
  /etc
  /etc/dbus-1
  /etc/dbus-1/system.d
  /etc/dbus-1/system.d/org.sdbuscpp.integrationtests.conf

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>
Cc: Stanislav Angelovic <58c90ff1fa7da3aed099d40aa21cbb34ea4cf360@gmail.com>

schnitzeltony/meta-openembedded,VCTLabs/meta-openembedded,schnitzeltony/meta-openembedded,rehsack/meta-openembedded,VCTLabs/meta-openembedded,openembedded/meta-openembedded,schnitzeltony/meta-openembedded,openembedded/meta-openembedded,moto-timo/meta-openembedded,schnitzeltony/meta-openembedded,rehsack/meta-openembedded,rehsack/meta-openembedded,VCTLabs/meta-openembedded,moto-timo/meta-openembedded,schnitzeltony/meta-openembedded,rehsack/meta-openembedded,openembedded/meta-openembedded,moto-timo/meta-openembedded,moto-timo/meta-openembedded,openembedded/meta-openembedded,rehsack/meta-openembedded,openembedded/meta-openembedded,VCTLabs/meta-openembedded,VCTLabs/meta-openembedded,VCTLabs/meta-openembedded,openembedded/meta-openembedded,openembedded/meta-openembedded,openembedded/meta-openembedded,VCTLabs/meta-openembedded,rehsack/meta-openembedded,rehsack/meta-openembedded,moto-timo/meta-openembedded,schnitzeltony/meta-openembedded,VCTLabs/meta-openembedded,schnitzeltony/meta-openembedded