Docs: admin/kernel-parameters: edit a few boot options

Docs: admin/kernel-parameters: edit a few boot options

Clean up some of admin-guide/kernel-parameters.txt:

a. "smt" should be "smt=" (S390)
b. (dropped)
c. Sparc supports the vdso= boot option
d. make the tp_printk options (2) formatting similar to other options
   by adding spacing
e. add "trace_clock=" with a reference to Documentation/trace/ftrace.rst
f. use [IA-64] as documented instead of [ia64]
g. fix formatting and text for test_suspend=
h. fix formatting for swapaccount=
i. fix formatting and grammar for video.brightness_switch_enabled=

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-ia64@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>