[LEDE-DEV] Add Synopsys brand to Wiki

[Alexey Brodkin]

Hello,

I wanted to add information about Synopsys boards (ARC 770D and ARC HS38 based)
in the "Table of Hardware" here https://wiki.openwrt.org/toh/.

Is there a chance to add new brand "Synopsys" to ToH?

For reference:
 * Support of ARC770-based boards: https://git.lede-project.org/?p=source.git;a=tree;f=target/linux/arc770
 * Support of ARC HS38-based boards: https://git.lede-project.org/?p=source.git;a=tree;f=target/linux/archs38

-Alexey