Some images may have multiple copies of the same thing, e.g. two versions
of the read/write U-Boots. It is necessary to read data from one or other
of these under selection of the verified-boot logic. Add a function to
select the subnode to use.

Signed-off-by: Simon Glass <sjg@chromium.org>

Provide a function to read the ROM offset so that we can store the value
in one place and clients don't need to store it themselves after calling
binman_set_rom_offset().

Signed-off-by: Simon Glass <sjg@chromium.org>

Add support for accessing an entry's contents in memory-mapped SPI flash.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

On x86 the SPI ROM can be memory-mapped, at least most of it. Add a way
to tell binman the offset from a ROM address to a RAM address.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

SPL and TPL can access information about binman entries using link-time
symbols but this is not available in U-Boot proper. Of course it could be
made available, but the intention is to just read the device tree.

Add support for this, so that U-Boot can locate entries.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>