rockchip: defconfig: puma-rk3399: enable RK808 support

rockchip: defconfig: puma-rk3399: enable RK808 support

On the RK3399-Q7, we need PMIC support (for the RK808) to enable HDMI
output, as one of the required powerrails is not enabled on boot.
For this, we need to enable the RK808 driver.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Version-changes: 3
- With the recent upstream changes to the RK808 (PMIC) driver, the
  associated configuration options have been renamed to RK8XX.  Track
  this change in the RK3399-Q7 defconfig.
Reviewed-by: Simon Glass <sjg@chromium.org>