Reverse RTTY and RTTYR in kenwood.c mode table

It was backwards.  RTTY is LSB (ie FSKR) and RTTYR is USB (ie FSK)
So RTTYR is mode 6 and RTTY is mode 9
https://github.com/Hamlib/Hamlib/issues/576

rigs/kenwood/kenwood.c

@@ -142,10 +142,12 @@ rmode_t kenwood_mode_table[KENWOOD_MODE_TABLE_MAX] =
     [3] = RIG_MODE_CW,
     [4] = RIG_MODE_FM,
     [5] = RIG_MODE_AM,
-    [6] = RIG_MODE_RTTY,
+    // Yes -- RTTYR is Mode 6 RTTY is LSB, RTTYR USB
+    // FSK mode is mapped the other way round
+    [6] = RIG_MODE_RTTYR, // FSK Mode
     [7] = RIG_MODE_CWR,
     [8] = RIG_MODE_NONE,  /* TUNE mode */
-    [9] = RIG_MODE_RTTYR,
+    [9] = RIG_MODE_RTTY,  // FSKR Mode
     [10] = RIG_MODE_PSK,
     [11] = RIG_MODE_PSKR,
     [12] = RIG_MODE_PKTLSB,

rigs/kenwood/kenwood.h

@@ -28,7 +28,7 @@
 #include "token.h"
 #include "misc.h"
 
-#define BACKEND_VER "20210221"
+#define BACKEND_VER "20210302"
 
 #define EOM_KEN ';'
 #define EOM_TH '\r'