spi: fix st7735 timing issue

Author: redchenjs

main/src/chip/spi.c

@@ -36,10 +36,11 @@ void hspi_init(void)
     spi_device_interface_config_t devcfg = {
         .mode = 0,                                // SPI mode 0
         .spics_io_num = CONFIG_SPI_CS_PIN,        // CS pin
-        .clock_speed_hz = 40000000,               // Clock out at 40 MHz
 #ifdef CONFIG_SCREEN_PANEL_ST7735
+        .clock_speed_hz = 26000000,               // Clock out at 26 MHz
         .pre_cb = st7735_setpin_dc,               // Specify pre-transfer callback to handle D/C line
 #elif defined(CONFIG_SCREEN_PANEL_ST7789)
+        .clock_speed_hz = 40000000,               // Clock out at 40 MHz
         .pre_cb = st7789_setpin_dc,               // Specify pre-transfer callback to handle D/C line
 #endif
         .queue_size = 2,                          // We want to be able to queue 2 transactions at a time