dm: core: Report bootph-pre-ram/sram node as pre-reloc after relocation

Nodes with bootph-pre-sram/ram props are bound in multiple phases:
1. At TPL (bootph-pre-sram) or SPL (bootph-pre-ram) phase
2. At U-Boot proper pre-relocation phase
3. At U-Boot proper normal phase

However the binding and U-Boot Driver Model documentation indicate that
only nodes marked with bootph-all or bootph-some-ram should be bound in
the U-Boot proper pre-relocation phase.

Change ofnode_pre_reloc to report a node with bootph-pre-ram/sram prop
with a pre-reloc status only after U-Boot proper pre-relocation phase.
Also update the ofnode_pre_reloc documentation to closer reflect the
binding and driver model documentation.

This changes behavior of what nodes are bound in the U-Boot proper
pre-relocation phase. Change to bootph-all or add bootph-some-ram prop
to restore prior behavior.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>