rockchip: rk3399: spl: remove hard-coded addresses for GRF and SGRF

rockchip: rk3399: spl: remove hard-coded addresses for GRF and SGRF

On the RK3399, we will have either OF_PLATDATA or full OF_CONTROL
enabled: this allows the use of syscon to retrieve the addresses of
GRF and SGRF (except for the early debug UART setup, which runs so
early that the device-model is not initialised).

This removes the hard-coded addresses and goes through syscon to
retrieve the base-addresses of GRF and SGRF. After that, we use
the structure definitions to locate the respective registers.

In addition to this, the inclusion of header files is also cleaned up:
- all headers are included at the beginning (there was a spurious
  inclusion of the grf header from within a function)
- all #include statements for unused headers are removed
- the remaining #include statements are sorted (while keeping common.h
  included in front)

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>