onewire_network: add a 'Disable Test Mode' command for DS2408

onewire_network: add a 'Disable Test Mode' command for DS2408

For details see the DS2408 datasheet, section "Power-up timing".

This commit is adding this missing command so now a full decoding
is possible:
Annotations from 1-Wire network layer:
8990980-8991220 1-Wire network layer: : Reset/presence: true
8994163-8994437 1-Wire network layer: : ROM command: 0x96 'DS2408: Disable Test Mode'
8995026-9008178 1-Wire network layer: : ROM: 0xa30000001246a929
9008785-9009060 1-Wire network layer: : Data: 0x3c
9012290-9012530 1-Wire network layer: : Reset/presence: true

And from the specific stacked DS2408 slave:
8990980-8991220 DS2408: : Reset/presence: true
8995026-9008178 DS2408: : ROM: 0xa30000001246a929 (family code 0x29)
9008785-9009060 DS2408: : Disable Test Mode (0x3c)
9012290-9012530 DS2408: : Reset/presence: true