usb: typec: ucsi: ccg: add firmware flashing support

CCGx has two copies of the firmware in addition to the bootloader.
If the device is running FW1, FW2 can be updated with the new version.
Dual firmware mode allows the CCG device to stay in a PD contract and
support USB PD and Type-C functionality while a firmware update is in
progress.

First we read the currently flashed firmware version of both
primary and secondary firmware and then compare it with
version of firmware file to determine if flashing is required.

Command framework is added to support sending commands to CCGx
controller. We wait for response after sending the command and then
read the response from RAB_RESPONSE register.

Below commands are supported,
	- ENTER_FLASHING
	- RESET
	- PDPORT_ENABLE
	- JUMP_TO_BOOT
	- FLASH_ROW_RW
	- VALIDATE_FW

Command specific mutex lock is also added to sync between driver
and user threads.

PD port number information is added which is required while sending
PD_PORT_ENABLE command

Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
[ heikki: Added ABI documentation. ]
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-driver-ucsi-ccg

@@ -0,0 +1,6 @@
+What:		/sys/bus/i2c/drivers/ucsi_ccg/.../do_flash
+Date:		May 2019
+Contact:	Ajay Gupta <ajayg@nvidia.com>
+Description:
+		Tell the driver for Cypress CCGx Type-C controller to attempt
+		firmware upgrade by writing [Yy1] to the file.