FROMLIST: arm64: Move esr_comment() to <asm/esr.h>

As it is already defined twice and is about to be needed for kCFI error
detection, move esr_comment() to a header for re-use, with a clearer
name.

Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>

Bug: 278010198
Link: https://lore.kernel.org/r/20240510112645.3625702-9-ptosi@google.com


Change-Id: I5550eb40d2cf280a5216c8e5d61d18bf13a7cb2a
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>