doc: using: dbus case sensitivity
doc: using: dbus case sensitivity

use correct upper and lower case for dbus interface and method/property

Signed-off-by: Jan Remmet <9c9945a0da87ab3eec6bcf12544e291bfd78ecfe@phytec.de>

jluebbe/rauc,jluebbe/rauc,ejoerns/rauc,rauc/rauc,jluebbe/rauc,ejoerns/rauc,rauc/rauc,ejoerns/rauc,rauc/rauc