aarch64: Create definitions for AARCH64_RA_SIGN_STATE register

This register will be used to indicate whether a return address is
mangled with a PAC or not, in accordance with the DWARF AARCH64 ABI [1].

[1] https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#41dwarf-register-names

Signed-off-by: German Gomez <german.gomez@arm.com>
[SteveC: move DW_AARCH64_RA_SIGN_STATE to cfi.h, fix comments]
Signed-off-by: Steve Capper <steve.capper@arm.com>
5 files changed