feat(adapter-riscv): replace static mut with KernelCell, complete all 17 syscall decoders, wire timer and PLIC interrupts to kernel

crates/types/src/permission.rs

@@ -41,7 +41,6 @@ impl PermissionSet {
         self.0 & other.0 == self.0
     }
 
-    #[cfg(kani)]
     pub fn from_bits(bits: u8) -> Self {
         PermissionSet(bits)
     }