arm64: dts: ti: k3-am6*: Add boot phase flag to support MMC boot

arm64: dts: ti: k3-am6*: Add boot phase flag to support MMC boot

The bootph-all flag was introduced in dt-schema
(dtschema/schemas/bootph.yaml) to define node usage across
different boot phases.

For eMMC and SD boot modes, voltage regulator nodes, io-expander
nodes, gpio nodes, and MMC nodes need to be present in all boot
stages, so add missing bootph-all phase flag to these nodes to
support SD boot and eMMC boot.

Signed-off-by: Judith Mendez <jm@ti.com>
Reviewed-by: Moteen Shah <m-shah@ti.com>
Link: https://lore.kernel.org/r/20250429151454.4160506-2-jm@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>