esp32/machine_hw_spi: Make HW SPI objects statically allocated.

This aligns more closely with the hardware, that there are two, fixed HW
SPI peripherals.  And it allows to recreate the HW SPI objects without
error, as well as create them again after a soft reset.

Fixes issue #4103.

ports/esp32/machine_hw_spi.c

@@ -58,6 +58,9 @@ typedef struct _machine_hw_spi_obj_t {
     } state;
 } machine_hw_spi_obj_t;
 
+// Static objects mapping to HSPI and VSPI hardware peripherals
+STATIC machine_hw_spi_obj_t machine_hw_spi_obj[2];
+
 STATIC void machine_hw_spi_deinit_internal(machine_hw_spi_obj_t *self) {
     switch (spi_bus_remove_device(self->spi)) {
         case ESP_ERR_INVALID_ARG:
@@ -363,7 +366,12 @@ mp_obj_t machine_hw_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
-    machine_hw_spi_obj_t *self = m_new_obj(machine_hw_spi_obj_t);
+    machine_hw_spi_obj_t *self;
+    if (args[ARG_id].u_int == HSPI_HOST) {
+        self = &machine_hw_spi_obj[0];
+    } else {
+        self = &machine_hw_spi_obj[1];
+    }
     self->base.type = &machine_hw_spi_type;
 
     machine_hw_spi_init_internal(