build: fix typos

Change-Id: I5ecd37cc9eb6145076068b458f2a1d95587e8665
Reviewed-on: https://review.monogon.dev/c/monogon/+/631
Reviewed-by: Sergiusz Bazanski <serge@monogon.tech>
diff --git a/build/toolchain/llvm-efi/README.md b/build/toolchain/llvm-efi/README.md
index 522fcfd..5f1b9c8 100644
--- a/build/toolchain/llvm-efi/README.md
+++ b/build/toolchain/llvm-efi/README.md
@@ -9,7 +9,7 @@
 Usage
 -----
 
-To use this toolchain explicitely while building a `cc_binary`, do:
+To use this toolchain explicitly while building a `cc_binary`, do:
 
     bazel build --crosstool_top=//build/toolchain/llvm-efi:efi_cc_suite //foo/bar