ARM: dts: rockchip: Remove vdd_log from rk808, DCDC_REG1 on rk3288-vyasa

vdd_log, never used on DCDC_REG1 of rk808 from latest schematic so
remove the same and update the regulator-name as 'vdd_arm' to sync
with existing rk3288 board dts files.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>