rust-cross: Add ppc support
rust-cross: Add ppc support

This ensures that rust-cross can be compiled for ppc arch

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

meta-rust/meta-rust,meta-rust/meta-rust,meta-rust/meta-rust,meta-rust/meta-rust,meta-rust/meta-rust