Ensure power on 0xfe's are flushed for Icom rigs

https://github.com/Hamlib/Hamlib/issues/900

rigs/icom/icom.c

@@ -7762,6 +7762,8 @@ int icom_set_powerstat(RIG *rig, powerstat_t status)
         memset(fe_buf, 0xfe, fe_max);
         // sending more than enough 0xfe's to wake up the rs232
         write_block(&rs->rigport, fe_buf, fe_max);
+        hl_usleep(200*1000); // short sleep
+        rig_flush(&rs->rigport); // flush any echo of 0xFE
 
         // we'll try 0x18 0x01 now -- should work on STBY rigs too
         pwr_sc = S_PWR_ON;

rigs/icom/icom.h

@@ -30,7 +30,7 @@
 #include <sys/time.h>
 #endif
 
-#define BACKEND_VER "20211214"
+#define BACKEND_VER "20211222"
 
 #define ICOM_IS_SECONDARY_VFO(vfo) ((vfo) & (RIG_VFO_B | RIG_VFO_SUB | RIG_VFO_SUB_B | RIG_VFO_MAIN_B))
 #define ICOM_GET_VFO_NUMBER(vfo) (ICOM_IS_SECONDARY_VFO(vfo) ? 0x01 : 0x00)