dt-bindings: riscv: Add Sha and its comprised extensions

dt-bindings: riscv: Add Sha and its comprised extensions

Add descriptions for the Sha extension and the seven extensions it
comprises: Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
and Ssstateen.

Sha is ratified in the RVA23 Profiles Version 1.0 (commit 0273f3c921b6
"rva23/rvb23 ratified") as a new profile-defined extension that captures
the full set of features that are mandated to be supported along with
the H extension.

Extensions Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
and Ssstateen are ratified in the RISC-V Profiles Version 1.0 (commit
b1d806605f87 "Updated to ratified state").

The requirement status for Sha and its comprised extension in RISC-V
Profiles are:
 - Sha: Mandatory in RVA23S64
 - H: Optional in RVA22S64; Mandatory in RVA23S64
 - Shcounterenw: Optional in RVA22S64; Mandatory in RVA23S64
 - Shgatpa: Optional in RVA22S64; Mandatory in RVA23S64
 - Shtvala: Optional in RVA22S64; Mandatory in RVA23S64
 - Shvsatpa: Optional in RVA22S64; Mandatory in RVA23S64
 - Shvstvala: Optional in RVA22S64; Mandatory in RVA23S64
 - Shvstvecd: Optional in RVA22S64; Mandatory in RVA23S64
 - Ssstateen: Optional in RVA22S64; Mandatory in RVA23S64

Signed-off-by: Guodong Xu <guodong@riscstar.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>