arm64: stacktrace: fix kerneldoc comments

arm64: stacktrace: fix kerneldoc comments

Many of the comment blocks in the arm64 stacktrace code are *almost*
kerneldoc, but not quite.

Convert them to kerneldoc, as was presumably originally intended.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: Fuad Tabba <tabba@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220901130646.1316937-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>