soc: xtensa: cavstool: add support for logs coming from HDA logging

1) HDA logging seems to be using some padding like '\x00'. Such
string can print well on a terminal but corrupt the string match.
And this can cause false failure if RunID matching is affected.
Remove such padding before checking RunID.

An affected RunID example:
'7aa9ba3c6db12\x00\...\x00\x00\x00\x00d0c7fcf382a4af40ec6'

Expected:
'7aa9ba3c6db12d0c7fcf382a4af40ec6'

2) Use non-displayable chars for live connection check. Otherwise
the log output will have subtle garbage like extra spaces which
locate randomly.

This solution comes from the PR #50071, the author is smrtos.

Signed-off-by: Ming Shao <ming.shao@intel.com>
Signed-off-by: Enjia Mai <enjia.mai@intel.com>