guix: remove no-longer needed powerpc workaround

Author: fanquake

contrib/guix/libexec/build.sh

@@ -238,13 +238,6 @@ case "$HOST" in
     *mingw*)  HOST_LDFLAGS="-Wl,--no-insert-timestamp" ;;
 esac
 
-# Using --no-tls-get-addr-optimize retains compatibility with glibc 2.18, by
-# avoiding a PowerPC64 optimisation available in glibc 2.22 and later.
-# https://sourceware.org/binutils/docs-2.35/ld/PowerPC64-ELF64.html
-case "$HOST" in
-    *powerpc64*) HOST_LDFLAGS="${HOST_LDFLAGS} -Wl,--no-tls-get-addr-optimize" ;;
-esac
-
 # Make $HOST-specific native binaries from depends available in $PATH
 export PATH="${BASEPREFIX}/${HOST}/native/bin:${PATH}"
 mkdir -p "$DISTSRC"