iio: dac: ltc2664: Device class for LTC2664 4 channel DAC #1633

All 260 tests pass, 1 169 skipped in 9m 19s

1 429 tests ±0   260 ✔️ ±0 9m 19s ⏱️ -2s
      1 suites ±0 1 169 💤 ±0
      1 files ±0       0 ❌ ±0

Results for commit f34b02a. ± Comparison against earlier commit 3242273.