[PATCH v4 25/42] dm: core: Add an option to support SPL in read-only memory

[Simon Glass]

Some systems (e.g. x86 APL) run SPL from read-only memory. The device
instances created by dtoc are therefore not writeable. To make things work
we would need to copy the devices to read/write memory.

To avoid this, add an option to use a separate runtime struct for devices,
just as is done for drivers. This can be used to hold information that
changes at runtime, avoiding the need for a copy.

Also add a Kconfig option for read-only SPL, which selects this feature.

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

(no changes since v1)

 common/spl/Kconfig | 24 ++++++++++++++++++++++++
 dts/Kconfig        | 22 ++++++++++++++++++++++
 2 files changed, 46 insertions(+)

Applied to u-boot-dm/next, thanks!