We only need to set the system up for a soft-restart if we're going to
be doing a soft-restart.  Provide a new function (soft_restart()) which
does the setup and final call for this, and make platforms use it.
Eliminate the call to setup_restart() from the default handler.

This means that platforms arch_reset() function is no longer called with
the page tables prepared for a soft-restart, and caches will still be
enabled.
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NViresh Kumar <viresh.kumar@st.com>
Acked-by: NKrzysztof Ha■asa <khc@pm.waw.pl>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NRichard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: NWan ZongShun <mcuos.com@gmail.com>
Acked-by: NEric Miao <eric.y.miao@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>