Update bootloader to pass boot location on kernel command line

Our planned boot-location-agnostic software will need this information
from the bootloader in order to find /system and /data.  Older software
will just ignore the added argument on the command line.

Built from commit 54951a2 ("omap3621_evt1a: pass boot device information
on kernel command line") in the encore_cyanoboot tree:
https://github.com/NookieDevs/encore_cyanoboot/tree/54951a274d28f5d21f6fe9a951852264aab32172

Change-Id: I0e2b40808e366f3af553b92663bfe2051b7348a0