Globally define BOARD_RECOVERY_BLDRMSG_OFFSET with a decimal integer
to offset the read/write location in misc where the bootloader message
should appear. Example:
BOARD_GLOBAL_CFLAGS := -DBOARD_RECOVERY_BLDRMSG_OFFSET=2048
Edify commands get_stage and set_stage need to be aware of the
custom bootloader msg offset because they write the stage directly
to the BCB.
Change-Id: Ifdb5ffe3e893a651be59ae63e3a0ebadd828c9f2
bootloader_messages merges bootloader_message_writer
and bootloader.cpp, so we can use the same library to
manage bootloader_message in normal boot and recovery mode.
Bug: 29582118
Change-Id: I9efdf776ef8f02b53911ff43a518e035e0c29618
