staging: android: ram_console: pass in a boot info string

Allow the board file to pass a boot info string through the
platform data that is appended to the /proc/last_kmsg file.

[moved the .h file to drivers/staging/android/ to be self-contained - gregkh]

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>