cores: uart16550: fix wb slave behavior

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
systems: add Altera de1 board support

This is a minimal port. VGA, SD-CARD and PS2 will come later.

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
Merge branch 'for-upstream-new' of https://github.com/fjullien/orpsoc-cores
Merge branch 'for-openrisc' of https://github.com/skristiansson/orpsoc-cores
Merge branch 'for-openrisc-de1' of https://github.com/fjullien/orpsoc-cores
systems/de0_nano: fix .system syntax

Remove simulation related options

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
systems/de1: fix .core and .system syntax

de1.core:

- remove leading spaces from simulator options
- add modelsim to the list of supported simulator

de1.system:

- Remove simulator related options

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
cores: add opencores ac97 controller core
cores: add opencores i2c master controller core