ARM: shmobile: Avoid writing to .text

Hi Simon, Magnus,

When CONFIG_DEBUG_RODATA=y, the kernel crashes during system suspend:

Freezing user space processes ... (elapsed 0.004 seconds) done. Freezing remaining freezable tasks ... (elapsed 0.002 seconds) done.
PM: suspend of devices complete after 111.948 msecs
PM: late suspend of devices complete after 1.086 msecs
PM: noirq suspend of devices complete after 11.576 msecs Disabling non-boot CPUs ...
Kernel panic - not syncing: Attempted to kill the idle task! 1014ec ---[ end Kernel panic - not syncing: Attempted to kill the idle task!
CPU0: stopping

This happens because the shmobile assembler sources have several variables that are written to in the .text section, while .text is mapped read-only after kernel bootup if CONFIG_DEBUG_RODATA=y.

This series fixes this by moving variables from .text to .bss, or just removing them.
Note that there's still an issue with shmobile_boot_fn in arch/arm/mach-shmobile/headsmp.S. So far I didn't manage to fix this (the code and data are copied to SRAM on some SoCs). However, currently this is mostly harmless, as this is written to during early kernel boot up only, before .text is marked read-only. It does matter for XIP (anyone using that with SMP?), so we do want to fix that in the long run, too.

These issues were uncovered by "[PATCH v2] ARM: mm: flip priority of CONFIG_DEBUG_RODATA". As that patch is already queued in arm/for-next, I think all these fixes should be queued for v4.5, to avoid a dependency with the arm tree.