Remove Wys systemd .conf file

Wys now has a configuration database based on the machine name.  We no
longer need to have configuration files in device-specific packages.

debian/control

@@ -19,6 +19,7 @@ Depends:
  mmc-utils,
  rfkill,
  u-boot-tools,
+Breaks: wys (<< 0.1.1~)
 Description: Basic configuration for the librem5-devkit
  This package contains initial configuration for the
  librem5 devkits.

usr/lib/systemd/user/wys.service.d/librem5-devkit.conf

-[Service]
-Environment=WYS_CODEC=sgtl5000
-Environment=WYS_MODEM="SIMCom SIM7100"