soc_core: Don't fail if name is the same.

soc_core: Don't fail if name is the same.

Otherwise you can't override the UART with another UART, you get an
error like;

```
  File "/home/tansell/github/timvideos/HDMI2USB-litex-firmware/third_party/litex/litex/soc/integration/soc_core.py", line 176, in __init__
    interrupt, mod_name, interrupt_rmap[interrupt]))
AssertionError: Interrupt vector conflict for IRQ 2, user defined uart conflicts with SoC inbuilt uart
```