greybus: gb-beagleplay: Add firmware upload API

Register with firmware upload API to allow updating firmware on cc1352p7
without resorting to overlay for using the userspace flasher.

Communication with the bootloader can be moved out of gb-beagleplay
driver if required, but I am keeping it here since there are no
immediate plans to use the on-board cc1352p7 for anything other than
greybus (BeagleConnect Technology). Additionally, there do not seem to
any other devices using cc1352p7 or it's cousins as a co-processor.

Boot and Reset GPIOs are used to enable cc1352p7 bootloader backdoor for
flashing. The delays while starting bootloader are taken from the
userspace flasher since the technical specification does not provide
sufficient information regarding it.

Flashing is skipped in case we are trying to flash the same
image as the one that is currently present. This is determined by CRC32
calculation of the supplied firmware and Flash data.

We also do a CRC32 check after flashing to ensure that the firmware was
flashed properly.

Firmware size should be 704 KB.

Link: https://www.ti.com/lit/ug/swcu192/swcu192.pdf Ti CC1352p7 Tecnical Specification
Link: https://openbeagle.org/beagleconnect/cc1352-flasher Userspace
Flasher

Signed-off-by: Ayush Singh <ayush@beagleboard.org>
Link: https://lore.kernel.org/r/20240903-beagleplay_fw_upgrade-v4-3-526fc62204a7@beagleboard.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Ayush1325

drivers/greybus/Kconfig

@@ -21,6 +21,8 @@ config GREYBUS_BEAGLEPLAY
 	tristate "Greybus BeaglePlay driver"
 	depends on SERIAL_DEV_BUS
 	select CRC_CCITT
+	select FW_LOADER
+	select FW_UPLOAD
 	help
 	  Select this option if you have a BeaglePlay where CC1352
 	  co-processor acts as Greybus SVC.