arc: Add support for HS Development Kit board

ARC HS Development Kit board is a new low-cost
development platform sporting ARC HS38 in real silicon
with nice set of features such as:
* Quad-core AR

arc: Add support for HS Development Kit board

ARC HS Development Kit board is a new low-cost
development platform sporting ARC HS38 in real silicon
with nice set of features such as:
* Quad-core ARC HS38 with 512 kB L2 cache and running @1GHz
* 4Gb of DDR (we use only lowest 1Gb out of it now)
* Lots of DesigWare peripherals
* Different connectivity modules:
- Synopsys HAPS HT3
- Arduino-compatible connector
- MikroBUS

This initial commit supports the following peripherals:
* UART (DW 8250)
* Ethernet (DW GMAC)
* SD/MMC (DW Mobile Storage)
* USB 1.1 & 2.0

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

show more ...