build: update sbi-spec to 0.0.6

Signed-off-by: YdrMaster <ydrml@hotmail.com>

Author: YdrMaster

CHANGELOG.md

@@ -16,7 +16,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - Use instance based RustSBI interface, with separate functions for legacy stdio
 - Update sbi-testing to version 0.0.1
-- Update sbi-spec to version 0.0.5
+- Update sbi-spec to version 0.0.6
 - Use crate *fast-trap* version 0.0.1 in rustsbi-qemu for trap handling
 - Use crate *rcore-console* version 0.0.0 in rustsbi-qemu and test-kernel for `print!` and `println!`
 - Use crate *aclint* version 0.0.0 in rustsbi-qemu for aclint structs