Zvk: Implement Zvksh, vector SM3 Hash Function

Implement the Zvksh sub-extension, "ShangMi Suite: SM3 Hash
Function Instructions":
 - vsm3me.vv, message expansion,
 - vsm3c.vi, compression rounds.

This also introduces a SM3 specific header for common logic.

Co-authored-by: Raghav Gupta <rgupta@rivosinc.com>
Co-authored-by: Albert Jakieła <aja@semihalf.com>
Co-authored-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: Eric Gouriou <ego@rivosinc.com>