ARM: dts: omap3: n900: Correct obsolete TWL4030 power compatible

ARM: dts: omap3: n900: Correct obsolete TWL4030 power compatible

The "ti,twl4030-power-n900" compatible string is obsolete and is not
supported by any in-kernel driver. Currently, the kernel falls back to
the second entry, "ti,twl4030-power-idle-osc-off", to bind a driver to
this node.

Make this fallback explicit by removing the obsolete board-specific
compatible. This preserves the existing functionality while making the
DTS compliant with the new, stricter 'ti,twl.yaml' binding.

Fixes: daebabd578647 ("mfd: twl4030-power: Fix PM idle pin configuration to not conflict with regulators")
Signed-off-by: Jihed Chaibi <jihed.chaibi.dev@gmail.com>
Link: https://lore.kernel.org/r/20250914192516.164629-4-jihed.chaibi.dev@gmail.com
Signed-off-by: Kevin Hilman <khilman@baylibre.com>