[U-Boot] rockchip: rk3399: Initialize CPU B clock.

[Philipp Tomsich]

> This patch sets the PLL of CPU cluster B (BPLL) to 600 MHz.
> This decreases the boot time of Linux 4.19 by about 8%.
> 
> The 600 MHz are inspired by the 600 MHz used for LPLL initialization
> (came in with commit 9f636a249c1).
> 
> Tested on RK3399-Q7 on Haikou base board.
> 
> Signed-off-by: Christoph Muellner <christoph.muellner at theobroma-systems.com>
> ---
>  arch/arm/include/asm/arch-rockchip/cru_rk3399.h | 22 +++++--
>  drivers/clk/rockchip/clk_rk3399.c               | 79 ++++++++++++++++++++++---
>  2 files changed, 88 insertions(+), 13 deletions(-)
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>