SITL: Minor changes to simplify platform (#14501)

* SITL: Minor changes to simplify platform

* Update main.c

* Update platform.h

* As per @ledvinap review

src/main/main.c

@@ -31,7 +31,7 @@ void run(void);
 
 int main(int argc, char * argv[])
 {
-#ifdef SIMULATOR_BUILD
+#ifdef USE_MAIN_ARGS
     targetParseArgs(argc, argv);
 #else
     UNUSED(argc);
@@ -48,8 +48,8 @@ void FAST_CODE run(void)
 {
     while (true) {
         scheduler();
-#ifdef SIMULATOR_BUILD
-        delayMicroseconds_real(50); // max rate 20kHz
+#if defined(RUN_LOOP_DELAY_US) && RUN_LOOP_DELAY_US > 0
+        delayMicroseconds_real(RUN_LOOP_DELAY_US);
 #endif
     }
 }

src/main/pg/gps.c

@@ -32,7 +32,7 @@
 PG_REGISTER_WITH_RESET_TEMPLATE(gpsConfig_t, gpsConfig, PG_GPS_CONFIG, 4);
 
 PG_RESET_TEMPLATE(gpsConfig_t, gpsConfig,
-#if defined(SIMULATOR_BUILD) && defined(USE_VIRTUAL_GPS)
+#if defined(USE_VIRTUAL_GPS)
     .provider = GPS_VIRTUAL,
 #else
     .provider = GPS_UBLOX,

src/main/pg/gyrodev.c

@@ -35,10 +35,6 @@
 #include "drivers/sensor.h"
 #include "sensors/gyro.h"
 
-#ifdef SIMULATOR_BUILD
-#define GYRO_COUNT 1
-#endif
-
 #ifndef GYRO_1_CS_PIN
 #define GYRO_1_CS_PIN NONE
 #endif

src/platform/SIMULATOR/include/platform/platform.h

@@ -36,4 +36,8 @@
 
 #define I2CDEV_COUNT        0
 
+#define RUN_LOOP_DELAY_US 50 // max 20khz run loop frequency
+#define USE_MAIN_ARGS
+#define GYRO_COUNT 1 // 1 Gyro
+
 typedef void* ADC_TypeDef; // Dummy definition for ADC_TypeDef