toolchain-buildroot: fix s/Trigerring/Triggering/ typo

Reported-by: Thomas De Schampheleire <patrickdepinguin@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

toolchain/toolchain-buildroot/toolchain-buildroot.mk

@@ -8,7 +8,7 @@ TOOLCHAIN_BUILDROOT_SOURCE =
 
 BUILDROOT_LIBC = $(call qstrip,$(BR2_TOOLCHAIN_BUILDROOT_LIBC))
 
-# Trigerring the build of the host-gcc-final will automatically do the
+# Triggering the build of the host-gcc-final will automatically do the
 # build of binutils, uClibc, kernel headers and all the intermediate
 # gcc steps.