[bsp]imxrt1060 fix wrong image reference.

bsp/imxrt/imxrt1060-nxp-evk/README.md

@@ -158,7 +158,7 @@ The SPI interface provided by the MIMXRT1060-EVK onboard Arduino interface has d
 ![](./figures/11.png)
 
 Solder works must be done before next step:
-![](./figures/18.png)
+![](./figures/18.jpg)
 
 ### 4.1 Configure the onboard SPI peripherals
 

bsp/imxrt/imxrt1060-nxp-evk/README_zh.md

@@ -179,7 +179,7 @@ MIMXRT1060-EVK板载arduino接口提供的SPI接口与SD卡的SDIO接口使用
 ![](./figures/11.png)
 
 修改图示跳线：
-![](./figures/18.png)
+![](./figures/18.jpg)
 
 ### 4.1 配置板载SPI外设