ucm: find-card,find-device - add UCM variable support for arguments (Syntax 9)

ucm: find-card,find-device - add UCM variable support for arguments (Syntax 9)

Add variable support for all lookup arguments in find-card and find-device
substitutions. Variables are identified by $ prefix and only enabled for
Syntax 9+ to maintain backward compatibility.

Modified arguments with variable support:
- find-card: field, regex
- find-device: type, field, stream, regex

Example usage:
  ${find-card:field=$FieldName,regex=$Pattern,return=number}
  ${find-device:type=$DevType,stream=$StreamType,field=$FieldName,regex=$Pattern}

Signed-off-by: Jaroslav Kysela <perex@perex.cz>