fixed wrong spelling.

Author: LynnL4

boards.txt

@@ -54,6 +54,6 @@ seeed_arch_mix.menu.debug.on=On
 seeed_arch_mix.menu.debug.on.build.flags.debug=-g
 seeed_arch_mix.menu.speed.600= 600 MHz (standard)
 seeed_arch_mix.menu.speed.600.build.f_cpu=600000000L
-seeed_arch_mix.menu.flash.QSPI=QSPI (defalut)
-seeed_arch_mix.menu.debug.on.build.flags.flash=-DQSPI_FLASH
+seeed_arch_mix.menu.flash.QSPI=QSPI (default)
+seeed_arch_mix.menu.flash.QSPI.build.flags.flash=-DQSPI_FLASH
 seeed_arch_mix.menu.flash.Hyper=Hyper