msm: camera: Convert VFE into platform device

Make VFE platform devices as well as
v4l2 sub-devices. They are created at system boot-up,
and registered during camera open.

The subdevices are decoupled from the v4l2 devices by
using device model APIs to find and register them.

Change-Id: I91a7144794505af23a6f32de58f1c7cc340f4882
Signed-off-by: Kevin Chan <ktchan@codeaurora.org>
diff --git a/arch/arm/mach-msm/devices.h b/arch/arm/mach-msm/devices.h
index ff3cfce..871a7d3 100644
--- a/arch/arm/mach-msm/devices.h
+++ b/arch/arm/mach-msm/devices.h
@@ -63,6 +63,7 @@
 extern struct platform_device msm8960_device_csid0;
 extern struct platform_device msm8960_device_csid1;
 extern struct platform_device msm8960_device_ispif;
+extern struct platform_device msm8960_device_vfe;
 
 extern struct platform_device apq8064_device_uart_gsbi1;
 extern struct platform_device apq8064_device_uart_gsbi3;