[chip-test] chip_sw_csrng_edn_cmd

### Test point name

[chip_sw_csrng_edn_cmd](https://github.com/lowRISC/opentitan/blob/0198bdd288578fa7ccacdced5865dd4a98445f07/hw/top_earlgrey/data/ip/chip_csrng_testplan.hjson#L9)

### Host side component

None

### OpenTitanTool infrastructure implemented

None

### Silicon Validation (SiVal)

Yes

### Emulation Targets

- [ ] None
- [x] CW310
- [ ] Hyperdebug + CW310

### Contact person

vogelpi

### Checklist

Please fill out this checklist as items are completed. Link to PRs and issues as appropriate.
- [ ] Check if existing test covers most or all of this testpoint (if so, either extend said test to cover all points, or skip the next 3 checkboxes)
- [ ] Device-side (C) component developed
- [ ] Bazel build rules developed
- [ ] Host-side component developed
- [ ] HJSON test plan updated with test name (so it shows up in the dashboard)
- [ ] Test added to dvsim nightly regression (and passing at time of checking)
- [ ] For SiVal test cases, test is running relevant FPGA or silicon regression

Effort estimation for adapting the existing test for silicon validation:
> estimate 2