stm32:stm32l15xxx pinmap Remove GPIO_SPEED_xxx and add legacy pinmap

Pinmaps should not have contained GPIO_SPEED_xxx settings.
   This is board dependent.

   This change adds CONFIG_STM32_USE_LEGACY_PINMAP to allow for
   lazy migration to using pinmaps without speeds.

   The work required to do this can be aided by running tools/stm32_pinmap_tool.py.
   The tools will take a board.h file and a legacy pinmap and outut the required
   changes that one needs to make to a board.h file.

   Eventually, STM32_USE_LEGACY_PINMAP will be deprecated and the legacy
   pinmaps removed from NuttX.

   Any new boards added should set STM32_USE_LEGACY_PINMAP=n and
   fully define the pins in board.h

arch/arm/src/stm32/hardware/stm32_pinmap.h

@@ -34,7 +34,11 @@
 /* STM32L15xx family */
 
 #  if defined(CONFIG_STM32_STM32L15XX)
-#    include "hardware/stm32l15xxx_pinmap.h"
+#    if defined(CONFIG_STM32_USE_LEGACY_PINMAP)
+#      include "hardware/stm32l15xxx_pinmap_legacy.h"
+#    else
+#      include "hardware/stm32l15xxx_pinmap.h"
+#    endif
 #  else
 #    error "Unsupported EnergyLite chip"
 #  endif