DataFlash: change unit ID of PWM to Y to remove conflict with deglongitude

Closes #9554 (thanks @wbrueg)

libraries/DataFlash/LogStructure.h

@@ -106,10 +106,10 @@ const struct UnitStructure log_Units[] = {
     { 'r', "rad" },           // radians
     { 'U', "deglongitude" },  // degrees of longitude
     { 'u', "ppm" },           // pulses per minute
-    { 'U', "us" },            // pulse width modulation in microseconds
     { 'v', "V" },             // Volt
     { 'P', "Pa" },            // Pascal
     { 'w', "Ohm" },           // Ohm
+    { 'Y', "us" },            // pulse width modulation in microseconds
     { 'z', "Hz" }             // Hertz
 };
 
@@ -1203,9 +1203,9 @@ Format characters in the format string for binary log messages
     { LOG_MESSAGE_MSG, sizeof(log_Message), \
       "MSG",  "QZ",     "TimeUS,Message", "s-", "F-"}, \
     { LOG_RCIN_MSG, sizeof(log_RCIN), \
-      "RCIN",  "QHHHHHHHHHHHHHH",     "TimeUS,C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13,C14", "sUUUUUUUUUUUUUU", "F--------------" }, \
+      "RCIN",  "QHHHHHHHHHHHHHH",     "TimeUS,C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13,C14", "sYYYYYYYYYYYYYY", "F--------------" }, \
     { LOG_RCOUT_MSG, sizeof(log_RCOUT), \
-      "RCOU",  "QHHHHHHHHHHHHHH",     "TimeUS,C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13,C14", "sUUUUUUUUUUUUUU", "F--------------"  }, \
+      "RCOU",  "QHHHHHHHHHHHHHH",     "TimeUS,C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13,C14", "sYYYYYYYYYYYYYY", "F--------------"  }, \
     { LOG_RSSI_MSG, sizeof(log_RSSI), \
       "RSSI",  "Qf",     "TimeUS,RXRSSI", "s-", "F-"  }, \
     { LOG_BARO_MSG, sizeof(log_BARO), \