greybus: firmware and svc: detect the difference between ES2 and ES3 chips

The Greybus SVC code needs to read and clear the module boot status upon
hotplug; this requires reading two different attributes depending on whether
we're running on ES2 or ES3.  On Marti Bolivar's (mbolivar@leaflabs.com)
advice, we detect ES2 using the unique ES2_DDBL1_MFR_ID and ES2_DDBL1_PROD_ID
for ES2 hardware, and treat all other chips as ES3 appropriately.  This patch
detects the difference and adds the appropriate definitions for ES3 hardware.

Signed-off-by: Eli Sennesh <esennesh@leaflabs.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>