UPSTREAM: lenovo/t400: Rewrite dock from t60

Old dock.c copied from x201 was incorrect. Do a rewrite of t60 dock
code as pnp devices.

Fixes USB and serial on the dock, if it is already connected when
computer is powered on. DVI and ethernet worked without this patch.

Hot-plug is yet to be fixed.

BUG=none
BRANCH=none
TEST=none

Change-Id: I7508874d9c821e31e2297ee5876a573b9eac990f
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 9ab5adbde4
Original-Change-Id: Ib20a0eff10d0cde92dd089baf4fca28b117dc999
Original-Signed-off-by: Kysti Mlkki <kyosti.malkki@gmail.com>
Original-Reviewed-on: https://review.coreboot.org/18054
Original-Tested-by: build bot (Jenkins)
Original-Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://chromium-review.googlesource.com/453375

src/ec/lenovo/h8/h8.h

@@ -28,9 +28,7 @@ int h8_ultrabay_device_present(void);
 u8 h8_build_id_and_function_spec_version(char *buf, u8 buf_len);
 void h8_usb_always_on(void);
 
-#if !IS_ENABLED (CONFIG_H8_DOCK_EARLY_INIT)
 void h8_mainboard_init_dock (void);
-#endif
 
 /* EC registers */
 #define H8_CONFIG0 0x00