ARM: mach-imx: move early resume code out of the .data section

Building the kernel with allyesconfig fails because the i.mx early
resume code located in the .data section is unable to fixup the bl
relocation as the branch target gets too far away.

The idea of having code in the .data section allows for easy access to
nearby data using relative addressing while the MMU is off. However it
is probably best to move the code back to the .text section where it
belongs and fixup the data access instead.  This solves the bl reloc
issue (at least until this becomes a general problem) and simplifies
the code as well.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>