Make DMR trunking state handling order-independent.

The CSBK slot type was only encoded into the ALOHA frame inside
setColorCode(), so it took effect only if a reconfigure happened after
an ALOHA frame had already been received; on the usual command ordering
(SET_CONFIG then ALOHA) the transmitted slot type depended entirely on
the host-supplied bytes. Remember the colour code and stamp the slot
type in writeAloha() as well.

Also clear m_controlChannel when trunking is disabled, so the host has
a way to stop control channel transmission other than rebooting, and
fix a stray tab introduced in createCACH().

DMRTX.h

@@ -83,6 +83,7 @@ private:
   bool                             m_abort[2U];
   bool                             m_controlChannel;
   bool                             m_trunking;
+  uint8_t                          m_colorCode;
 
   void createData(uint8_t slotIndex);
   void createCACH(uint8_t txSlotIndex, uint8_t rxSlotIndex);