PIN_PWR_DELAY_MS --> PERIPHERAL_WARMUP_MS (#8467)

It turns out we had two methods for delaying startup while peripherals
warmed up. They were invented within months of each other and just missed
the chance to merge.

Let's delete PIN_PWR_DELAY_MS and use PERIPHERAL_WARMUP_MS, since it's
most common and earlier in the sequence.

src/main.cpp

@@ -1186,11 +1186,6 @@ void setup()
 #endif
 #endif
 
-#ifdef PIN_PWR_DELAY_MS
-    // This may be required to give the peripherals time to power up.
-    delay(PIN_PWR_DELAY_MS);
-#endif
-
 #ifdef ARCH_PORTDUINO
     // as one can't use a function pointer to the class constructor:
     auto loraModuleInterface = [](LockingArduinoHal *hal, RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst,