src-test/sys/dev/goldfish, branch main

src-test/sys/dev/goldfish, branch main FreeBSD source tree https://cgit-dev.freebsd.org/src-test/atom?h=main 2020-07-26T18:15:16Z Add Goldfish RTC device driver for RISC-V 2020-07-26T18:15:16Z Jessica Clarke jrtc27@FreeBSD.org 2020-07-26T18:15:16Z urn:sha1:d63a631e72441687910b8ec4a9396ac5d05029fb This device was originally used as part of the goldfish virtual hardware platform used for emulating Android on QEMU, but is now also used as the RTC for the RISC-V virt machine in QEMU. It provides a simple 64-bit nanosecond timer exposed via a pair of memory-mapped 32-bit registers, although only with 1s granularity. Reviewed by: brooks (mentor), jhb (mentor), kp Approved by: brooks (mentor), jhb (mentor), kp Obtained from: CheriBSD Differential Revision: https://reviews.freebsd.org/D25717