Adjust code generated by regformats/regdat.sh

regformats/regdat.sh generate some *-generated.c files when GDBserver
is built.  Each .c file has some static variables, which are only used
within function init_registers_XXX, like this,

static struct reg regs_i386_linux[] = {
  { "eax", 0, 32 },
  { "ecx", 32, 32 },
  ...
};

static const char *expedite_regs_i386_linux[] = { "ebp", "esp", "eip", 0 };
static const char *xmltarget_i386_linux = "i386-linux.xml";

void
init_registers_i386_linux (void)
{
  ...
}

This patch moves these static variables' definitions to function
init_registers_XXX, so the generated files look like this,

void
init_registers_i386_linux (void)
{
  static struct target_desc tdesc_i386_linux_s;
  struct target_desc *result = &tdesc_i386_linux_s;
static struct reg regs_i386_linux[] = {
  ...
};

static const char *expedite_regs_i386_linux[] = { "ebp", "esp", "eip", 0 };
static const char *xmltarget_i386_linux = "i386-linux.xml";

  ...
}

We want GDBserver create target descriptions dynamically in each
init_registers_XXXX functions, so this patch moves all the related code
into function init_registers_XXXX, so that the following patch can easily
change function init_registers_XXXX to create target description
dynamically, rather than using current pre-generated array.

gdb:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* regformats/regdat.sh: Adjust code order.