[fb] Create fb driver

Create a new framebuffer driver. Also hackily passing frame buffer size
in the list of init handles to all processes and mapping the framebuffer
into all processes. Changed bootloader passing frame buffer as a module
to its own struct.

modules.yaml

@@ -87,6 +87,16 @@ modules:
             - src/drivers/nulldrv/main.s
             - src/drivers/nulldrv/serial.cpp
 
+    fb:
+        kind: exe
+        target: user
+        output: fb.elf
+        deps:
+          - libc
+        source:
+            - src/drivers/fb/main.cpp
+            - src/drivers/fb/main.s
+
     kutil:
         kind: lib
         output: libkutil.a