targets/de10lite: use external clock for sys directly

At the start output of the pll is not stabilized, which
caused malfunctions when used for sys clock domain.
Use AsyncResetSynchronizer to start clock domains
on pll locked signal.

add the Hackaday Supercon ECP5 badge

Update ecp5_evn.py

Add the Hackaday Supercon 2019 badge which has an ECP5 FPGA:
https://hackaday.io/project/167255-2019-hackaday-superconference-badge

These changes are from Michael Welling's fork:
https://github.com/mwelling/linux-on-litex-vexriscv

During Supercon, we trying two approaches:
- use the built-in 16MB QSPI SRAM
- use add-on cartiridge with 32MB SDRAM by Jacob Creedon

We were not able to get the QSPI SRAM working so I've removed
those changes, and I have just added the changes that are needed
to boot Linux with the 32MB SDRAM.

Thanks to Jacob Creedon, Greg Davill and Tim Ansell who helped debug.

KiCad design files for the SDRAM cartridge are available at:
https://github.com/jcreedon/dram-cart/

The SDRAM cartridge PCB is shared at:
https://oshpark.com/shared_projects/IQSl2lid

More information in this blog post:
https://blog.oshpark.com/2019/12/20/

The Hackaday Supercon badge PCB design is here:
https://github.com/Spritetm/hadbadge2019_pcb

Updating the templates for Fomu.

Adding initial support for Saanlima's Pipistrello LX45 board

targets/de10lite: rename VideoSoC to VGASoC (to avoid confusion with VideoSoC as used on Video designs with framebuffer)

Update de10lite platform

Add VideoSoC build option, based on Frank Buss example.

Use PLL to generate clock for both sys clock domain and clock domain
for sdram. Additionally set up clock domain for VGA periph.

Use single image with memory initialization
to make more space for SoC ROM sector.

V10 and W10 pins were used in UART periph, causing error
when gpio_0 were requested.

Fix numato csr headers

get_csr_header parameter with_shadow_base
removed/deprecated in litex 2a8d8c8f. New default
behavior matches the desired behavior in these targets.

litex commit 8be5824e258b84df240d34636aaa539124b92c65 simplified the handling
of csr regions and constants.

targets: keep attributes are no longer needed since automatically added when applying constraints to signals.