Add separate method to get free PSRAM and report only internal in getFreeHeap

Author: me-no-dev

Diff for: cores/esp32/Esp.cpp

@@ -114,7 +114,12 @@ void EspClass::restart(void)
 
 uint32_t EspClass::getFreeHeap(void)
 {
-    return esp_get_free_heap_size();
+    return heap_caps_get_free_size(MALLOC_CAP_INTERNAL);
+}
+
+uint32_t EspClass::getFreePsram(void)
+{
+    return heap_caps_get_free_size(MALLOC_CAP_SPIRAM);
 }
 
 uint8_t EspClass::getChipRevision(void)

Diff for: cores/esp32/Esp.h

@@ -57,6 +57,7 @@ class EspClass
     ~EspClass() {}
     void restart();
     uint32_t getFreeHeap();
+    uint32_t getFreePsram();
     uint8_t getChipRevision();
     uint8_t getCpuFreqMHz(){ return CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ; }
     uint32_t getCycleCount();