cmake: require libusb for usbview module

Look for libusb, using it for the usbview module.

Modules/CMakeLists.txt

 
 add_subdirectory( about-distro )
-add_subdirectory( usbview )
 add_subdirectory( memory )
 add_subdirectory( devinfo )
 add_subdirectory( info )
@@ -67,6 +66,17 @@ if(RAW1394_FOUND)
    add_subdirectory( view1394 )
 endif()
 
+find_package(USB1 MODULE)
+set_package_properties(USB1 PROPERTIES DESCRIPTION "library that provides generic access to USB devicess"
+                       URL "https://libusb.info/"
+                       TYPE OPTIONAL
+                       PURPOSE "View USB devices in kinfocenter"
+                      )
+
+if(USB1_FOUND)
+   add_subdirectory( usbview )
+endif()
+
 if (CMAKE_SYSTEM_NAME MATCHES Linux)
     add_subdirectory(energy)
     add_subdirectory(fileindexermonitor)

Modules/usbview/CMakeLists.txt

@@ -9,7 +9,7 @@ set(kcm_usb_PART_SRCS kcmusb.cpp usbdevices.cpp usbdb.cpp )
 add_library(kcm_usb MODULE ${kcm_usb_PART_SRCS})
 
 
-target_link_libraries(kcm_usb KF5::KCMUtils KF5::I18n)
+target_link_libraries(kcm_usb KF5::KCMUtils KF5::I18n Libusb-1.0)
 
 install(TARGETS kcm_usb  DESTINATION ${KDE_INSTALL_PLUGINDIR} )