ARM: dts: cm-t54: fix serial console power supply.

LDO8 regulator is used for act led and serial cosole power supply.

Its DT status is declared as "disabled", however the serial console was
functional until Commit 318dbb02 ("regulator: palmas: Fix SMPS
enable/disable/is_enabled") wich properly turns off LDO8 on boot.

Fix serial cosole power supply (and act led) on boot by turning LDO8 on.

Fixes: 318dbb02 ("regulator: palmas: Fix SMPS enable/disable/is_enabled")
Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Tested-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>