rust: Remove unneeded RUST_TARGETGENS settings

These match the default from the class so drop them. We then always
generate all targets so remove the configuration from the class.

(From OE-Core rev: e4d56256936c55bab2bf2934ccbde9157ef7dc57)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/cargo/cargo.inc

@@ -18,8 +18,6 @@ EXCLUDE_FROM_WORLD = "1"
 
 inherit cargo pkgconfig
 
-RUST_TARGETGENS = "BUILD HOST TARGET"
-
 do_cargo_setup_snapshot () {
 	${WORKDIR}/rust-snapshot-components/${CARGO_SNAPSHOT}/install.sh --prefix="${WORKDIR}/${CARGO_SNAPSHOT}" --disable-ldconfig
 	# Need to use uninative's loader if enabled/present since the library paths

meta/recipes-devtools/rust/libstd-rs.inc

@@ -12,9 +12,6 @@ DEPENDS:append:libc-musl = " libunwind"
 DEPENDS:remove:riscv32 = "libunwind"
 DEPENDS:remove:riscv64 = "libunwind"
 
-
-RUST_TARGETGENS = "BUILD HOST TARGET"
-
 # Embed bitcode in order to allow compiling both with and without LTO
 RUSTFLAGS += "-Cembed-bitcode=yes"
 # Needed so cargo can find libbacktrace

meta/recipes-devtools/rust/rust.inc

@@ -34,8 +34,6 @@ setup_cargo_environment () {
 
 inherit rust-target-config
 
-RUST_TARGETGENS = "BUILD HOST TARGET"
-
 do_rust_setup_snapshot () {
     for installer in "${WORKDIR}/rust-snapshot-components/"*"/install.sh"; do
         "${installer}" --prefix="${WORKDIR}/rust-snapshot" --disable-ldconfig