android: boot: Add set_abootimg_addr() and set_avendor_bootimg_addr()

android: boot: Add set_abootimg_addr() and set_avendor_bootimg_addr()

The only way to configure the load addresses for both bootimg and
vendor_bootimg is by using the "abootimg" command.
If we want to use the C API, there is no equivalent.

Add set_abootimg_addr() and set_avendor_bootimg_addr() so that we can
specify the load address from C.

This can be useful for implementing an Android bootmethod.

Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>
Reviewed-by: Julien Masson <jmasson@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Guillaume La Roque <glaroque@baylibre.com>
Tested-by: Guillaume La Roque <glaroque@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>