[U-Boot] efi_loader: Rename EFI_RUNTIME_{TEXT, DATA} to __efi_runtime{, _data}

[Alexander Graf]

> Compiler attributes are more commonly __foo style tags rather than big
> upper case eye sores like EFI_RUNTIME_TEXT.
> 
> Simon Glass felt quite strongly about this, so this patch converts our
> existing defines over to more eye friendly ones.
> 
> Signed-off-by: Alexander Graf <agraf at suse.de>
> Reviewed-by: Simon Glass <sjg at chromium.org>

Thanks, applied to efi-next