cpufeatures: requesting support for ermsb, fsrm target feature

[edman80]

fsrm: Fast Short REP MOVSB
ermsb: Enhanced REP MOVSB/STOSB

rust-lang already appears to include ermsb https://github.com/rust-lang/rust/blob/035b01b794602d5861daa43ac792f372f8981ed7/library/std_detect/src/detect/arch/x86.rs#L276