bootsource: add support for bootsource instance information
Add a C interface to set and get the bootsource instance:
int bootsource_get_instance(void);
void bootsource_set_instance(int instance);
Also export the shell variable "bootsource_instance".
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>