Convert override syntax to new version

For details see:
https://docs.yoctoproject.org/next/migration-guides/migration-3.4.html

Note that due to this change the latest point release of Dunfell is
the minimal requirement to be compatible with this layer.

recipes-integration/packagegroups/packagegroup-kde-applications.bb

@@ -8,7 +8,7 @@ LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda
 
 inherit packagegroup
 
-RDEPENDS_${PN} = " \
+RDEPENDS:${PN} = " \
     kdialog \
     kirigami-gallery \
     konsole \

recipes-integration/packagegroups/packagegroup-plasma-mobile-applications.bb

@@ -8,7 +8,7 @@ LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda
 
 inherit packagegroup
 
-RDEPENDS_${PN} = " \
+RDEPENDS:${PN} = " \
     alligator \
     calindori \
     kasts \

recipes-integration/packagegroups/packagegroup-plasma-mobile-workspace.bb

@@ -14,7 +14,7 @@ inherit packagegroup features_check
 
 REQUIRED_DISTRO_FEATURES = "wayland x11 kde"
 
-RDEPENDS_${PN} = " \
+RDEPENDS:${PN} = " \
     bluedevil \
     breeze \
     discover \

recipes-integration/packagegroups/packagegroup-plasma-mobile.bb

@@ -8,7 +8,7 @@ LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda
 
 inherit packagegroup
 
-RDEPENDS_${PN} = " \
+RDEPENDS:${PN} = " \
     packagegroup-plasma-mobile-workspace \
     packagegroup-plasma-mobile-applications \
 "