ARM: OMAP2+: Fix ppa_zero_params and ppa_por_params for rodata

We don't want to write to .text so let's move ppa_zero_params and
ppa_por_params to .data and access them via pointers.

Note that I have not been able to test as we I don't have a HS
omap4 to test with. The code has been changed in similar way as
for omap3 though.

Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org # v4.0+
Fixes: 1e6b4811

 ("ARM: mm: allow non-text sections to be
non-executable")
Signed-off-by: Tony Lindgren <tony@atomide.com>