Add new PocketBook PB-Basic Lux 4 (PB618) (#10987)

frontend/device/pocketbook/device.lua

@@ -506,6 +506,12 @@ local PocketBook617 = PocketBook:extend{
     hasNaturalLight = yes,
 }
 
+-- PocketBook Basic Lux 4 (618)
+local PocketBook618 = PocketBook:extend{
+    model = "PBBLux4",
+    display_dpi = 212,
+}
+
 -- PocketBook Touch (622)
 local PocketBook622 = PocketBook:extend{
     model = "PBTouch",
@@ -769,6 +775,8 @@ elseif codename == "PB616" or codename == "PB616W" or
     return PocketBook616
 elseif codename == "PB617" or codename == "PocketBook 617" then
     return PocketBook617
+elseif codename == "PB618" then
+    return PocketBook618
 elseif codename == "PocketBook 622" then
     return PocketBook622
 elseif codename == "PocketBook 623" then