[BUG] I2S operations are not adhered to by lower-half implementations

### Description / Steps to reproduce the issue

Some lower-half implementations of the I2S driver do not follow the correct return contract.

For instance, `i2s_txsamplerate` requires the return value to be the current bitrate. However, some drivers (i.e. `rp2040_i2s.c`) return 0 on success and a negated errno value on failure. This is not correct, it should be the bitrate on success.

https://github.com/apache/nuttx/blob/e9ac37e4272493d4d2e775d819b6bd9df2e90506/arch/arm/src/rp2040/rp2040_i2s.c#L737-L766

https://github.com/apache/nuttx/blob/e9ac37e4272493d4d2e775d819b6bd9df2e90506/include/nuttx/audio/i2s.h#L268-L287

### On which OS does this issue occur?

[OS: Linux]

### What is the version of your OS?

Arch Linux

### NuttX Version

master

### Issue Architecture

[Arch: all]

### Issue Area

[Area: Drivers]

### Host information

_No response_

### Verification

- [x] I have verified before submitting the report.