fix: Remove unused SPI pin configuration type

This union type was added in order to support the ESP32-PICO-V4,
and this workaround has been removed in the meantime.

Closes https://github.com/espressif/esp-serial-flasher/issues/71

idf_component.yml

@@ -1,3 +1,3 @@
-version: "0.3.0"
+version: "0.3.1"
 description: Serial flasher component provides portable library for flashing or loading ram loadble app to Espressif SoCs from other host microcontroller
 url: https://github.com/espressif/esp-serial-flasher

include/esp_loader.h

@@ -89,21 +89,6 @@ typedef struct {
     uint8_t *data;
 } esp_loader_bin_segment_t;
 
-/**
- * @brief SPI pin configuration arguments
- */
-typedef union {
-    struct {
-        uint32_t pin_clk: 6;
-        uint32_t pin_q:   6;
-        uint32_t pin_d:   6;
-        uint32_t pin_cs:  6;
-        uint32_t pin_hd:  6;
-        uint32_t zero:    2;
-    };
-    uint32_t val;
-} esp_loader_spi_config_t;
-
 /**
  * @brief Connection arguments
  */