SRV_Channel: move library-specific definitions into .h from _config.h

the _config.h files are *not* supposed to be some sort of externally-visible-vs-internally-visibly split for library defines.  They are expected to be the bare minimum to allow the feature defines to work.

Move as much information as sensible back from _config.h to .h file

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: peterbarker

libraries/SRV_Channel/SRV_Channel.h

@@ -25,6 +25,12 @@
 
 #include "SRV_Channel_config.h"
 
+#ifndef ACTUATOR_CHANNELS
+#define ACTUATOR_CHANNELS 6
+#endif
+
+#define ACTUATOR_DEFAULT_INCREMENT 0.01
+
 static_assert(NUM_SERVO_CHANNELS <= 32, "More than 32 servos not supported");
 
 class SRV_Channels;

libraries/SRV_Channel/SRV_Channel_config.h

@@ -6,12 +6,6 @@
 #define AP_SRV_CHANNELS_ENABLED 1
 #endif
 
-#ifndef ACTUATOR_CHANNELS
-#define ACTUATOR_CHANNELS 6
-#endif
-
-#define ACTUATOR_DEFAULT_INCREMENT 0.01
-
 #ifndef NUM_SERVO_CHANNELS
     #if HAL_PROGRAM_SIZE_LIMIT_KB > 1024
         #define NUM_SERVO_CHANNELS 32