Rockchip RK3328 support added to -current

[Jared McNeill <jmcneill%invisible.ca@localhost>]

Hi folks --

Support for the Rockchip RK3328 SoC has been committed to NetBSD -current.

RK3328 is a quad-core 64-bit ARM Cortex-A53 with integrated ethernet, 
USB 2.0/3.0/OTG, HDMI 2.0a, SD/MMC/SDIO controller, and Mali-450MP4 GPU.

The GENERIC64 kernel config in -current now has support for this SoC along 
with the following devices:

 - Clock and reset: rkcru
 - GPIO: rkgpio
 - Gigabit ethernet: awge
 - Pin controller: rkiomux
 - SD/MMC controller: dwcmmc
 - Serial UART: com
 - USB 2.0 PHY: rkusb, rkusbphy
 - USB 2.0 host: ehci
 - USB 1.1 host: ohci

Developed and tested on the ROCK64: 
https://www.pine64.org/?product=rock64-media-board-computer

Downloadable images for ROCK64 are available at 
http://www.invisible.ca/arm

Cheers,
Jared