Update boards.txt

Author: is-qian

boards.txt

@@ -34956,7 +34956,7 @@ XIAO_ESP32S3_PLUS.build.msc_on_boot=0
 XIAO_ESP32S3_PLUS.build.dfu_on_boot=0
 XIAO_ESP32S3_PLUS.build.f_cpu=240000000L
 XIAO_ESP32S3_PLUS.build.flash_size=8MB
-XIAO_ESP32S3.build.flash_freq=80m
+XIAO_ESP32S3_PLUS.build.flash_freq=80m
 XIAO_ESP32S3_PLUS.build.flash_mode=dio
 XIAO_ESP32S3_PLUS.build.boot=qio
 XIAO_ESP32S3_PLUS.build.boot_freq=80m