Revert "efi_loader: efi_allocate_pages is too restrictive"

This reverts commit aa909462. This change
caused "dhcp filename" to crash the system on p2371-2180 (Jetson TX1), for
example when running test/py.

Reverting this change isn't optimal, but at least restores TX1 to a working
state. In the future, we should:

a) Fix whatever problem causes the crash with this patch applied. This
needs further discussion, so isn't something we can immediately do.

b) Undo the revert; re-apply the original patch to efi_allocate_pages.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>