target/armv7m: fix feature name of ARMv8M security extension regs
gdb requires this feature to enable stack unwinding of secure/nonsecure
interstate calls and exceptions on an ARMv8M target with
the security extension.
Tested on STM32L5 (Cortex-M33).
Change-Id: Ib09780c011afbc095b352074068597559ad14fcd
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ae7e2f45aa4798be449f282bbf75ad41e73f055e
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7265
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>