greybus: firmware: Add firmware management bundle driver

All firmware packages on the Modules or Interfaces are now managed by a
special Firmware Management Protocol. The Interface Manifest shall
at least contain the Firmware Management Bundle and a Firmware
Management Protocol CPort within it.

The bundle may contain additional CPorts based on the extra
functionality required to manage firmware packages.

For example, this is how the Firmware Management Bundle of the Interface
Manifest may look like:

	; Firmware Management Bundle (Bundle 1):
	[bundle-descriptor 1]
	class = 0x16

	; (Mandatory) Firmware Management Protocol on CPort 1
	[cport-descriptor 1]
	bundle = 1
	protocol = 0x18

	; (Optional) Firmware Download Protocol on CPort 2
	[cport-descriptor 2]
	bundle = 1
	protocol = 0x17

	; (Optional) SPI protocol on CPort 3
	[cport-descriptor 3]
	bundle = 1
	protocol = 0x0b

	; (Optional) Component Authentication Protocol (CAP) on CPort 4
	[cport-descriptor 4]
	bundle = 1
	protocol = 0xXX //TBD

This patch adds the basic firmware-management bundle driver, which just
creates a firmware-management connection. Support for individual
protocols will be added separately.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>