Our definitions for bit 7 and bit 0 of ICL_PORT_TX_DW6 are
swapped. Functionally it doesn't matter as we always set both
bits, but let's rename the bits to match bspec 100%.

And while at it, add the definition for bits 1-6 as well, just
to have it all fully documented.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240308072400.28918-1-ville.syrjala@linux.intel.comReviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>