ucm: configuration - add DefineRegex

Syntax:

  DefineRegex.VariableName {
    String "something to match"
    Regex "(me)thi(ng)"
  }

Result:

- configuration variable "VariableName" is equal to "mething"
- configuration variable "VariableName1" is equal to "me"
- configuration variable "VariableName2" is equal to "ng"

Notes:

The "Flags" string in the DefineRegex compound may specify
the compilation flags (e = extended, i = ignore case,
s = no substitutes, n = newline). See 'man 3 regex' for
more details.

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

src/ucm/ucm_local.h

@@ -317,6 +317,10 @@ int uc_mgr_evaluate_condition(snd_use_case_mgr_t *uc_mgr,
 			      snd_config_t *parent,
 			      snd_config_t *cond);
 
+int uc_mgr_define_regex(snd_use_case_mgr_t *uc_mgr,
+			const char *name,
+			snd_config_t *eval);
+
 /** The name of the environment variable containing the UCM directory */
 #define ALSA_CONFIG_UCM_VAR "ALSA_CONFIG_UCM"