[posix-app] remove pseudo reset (#3190)

diff --git a/src/posix/main.c b/src/posix/main.c
index 8b58923..818787e 100644
--- a/src/posix/main.c
+++ b/src/posix/main.c
@@ -86,7 +86,7 @@
     otDiagInit(sInstance);
 #endif
 
-    while (!otSysPseudoResetWasRequested())
+    while (true)
     {
         otTaskletsProcess(sInstance);
         otSysProcessDrivers(sInstance);
diff --git a/src/posix/platform/misc.c b/src/posix/platform/misc.c
index 86e36a1..61f5f0c 100644
--- a/src/posix/platform/misc.c
+++ b/src/posix/platform/misc.c
@@ -38,26 +38,17 @@
 
 extern jmp_buf gResetJump;
 
-static otPlatResetReason   sPlatResetReason = OT_PLAT_RESET_REASON_POWER_ON;
-bool                       gPlatformPseudoResetWasRequested;
+static otPlatResetReason   sPlatResetReason   = OT_PLAT_RESET_REASON_POWER_ON;
 static otPlatMcuPowerState gPlatMcuPowerState = OT_PLAT_MCU_POWER_STATE_ON;
 
 void otPlatReset(otInstance *aInstance)
 {
-#if OPENTHREAD_PLATFORM_USE_PSEUDO_RESET
-    gPlatformPseudoResetWasRequested = true;
-    sPlatResetReason                 = OT_PLAT_RESET_REASON_SOFTWARE;
-
-#else // elif OPENTHREAD_PLATFORM_USE_PSEUDO_RESET
-
     otSysDeinit();
     platformUartRestore();
 
     longjmp(gResetJump, 1);
     assert(false);
 
-#endif // else OPENTHREAD_PLATFORM_USE_PSEUDO_RESET
-
     (void)aInstance;
 }
 
diff --git a/src/posix/platform/openthread-system.h b/src/posix/platform/openthread-system.h
index de8b2d1..2ad2e88 100644
--- a/src/posix/platform/openthread-system.h
+++ b/src/posix/platform/openthread-system.h
@@ -63,17 +63,6 @@
 void otSysDeinit(void);
 
 /**
- * This function returns true if a pseudo-reset was requested.
- *
- * In such a case, the main loop should shut down and re-initialize the OpenThread instance.
- *
- * @note This function is not called by the OpenThread library. Instead, the system/RTOS should call this function
- *       in the main loop to determine when to shut down and re-initialize the OpenThread instance.
- *
- */
-bool otSysPseudoResetWasRequested(void);
-
-/**
  * This function performs all platform-specific processing for OpenThread's example applications.
  *
  * @note This function is not called by the OpenThread library. Instead, the system/RTOS should call this function
diff --git a/src/posix/platform/system.c b/src/posix/platform/system.c
index fe80ac5..f572d70 100644
--- a/src/posix/platform/system.c
+++ b/src/posix/platform/system.c
@@ -49,8 +49,6 @@
 
 uint64_t gNodeId = 0;
 
-extern bool gPlatformPseudoResetWasRequested;
-
 static void PrintUsage(const char *aProgramName, FILE *aStream, int aExitCode)
 {
     fprintf(aStream,
@@ -71,12 +69,6 @@
     const char *radioFile     = NULL;
     const char *radioConfig   = "";
 
-    if (gPlatformPseudoResetWasRequested)
-    {
-        gPlatformPseudoResetWasRequested = false;
-        return;
-    }
-
     while (true)
     {
         int                 option;
@@ -150,11 +142,6 @@
     }
 }
 
-bool otSysPseudoResetWasRequested(void)
-{
-    return gPlatformPseudoResetWasRequested;
-}
-
 void otSysDeinit(void)
 {
 #if OPENTHREAD_POSIX_VIRTUAL_TIME