systemd: fix efi stubs

systemd: fix efi stubs

Before the patch:

| $ objdump -h deploy/images/intel-corei7-64/linuxx64.efi.stub
| objdump: deploy/images/intel-corei7-64/linuxx64.efi.stub (.reloc): section flag STYP_GROUP (0x4) ignored
| objdump: deploy/images/intel-corei7-64/linuxx64.efi.stub (.reloc): section flag STYP_GROUP (0x4) ignored
| objdump: deploy/images/intel-corei7-64/linuxx64.efi.stub: file format not recognized

After the patch:

| $objdump -h deploy/images/intel-corei7-64/linuxx64.efi.stub
|
| deploy/images/intel-corei7-64/linuxx64.efi.stub:     file format pei-x86-64
|
| Sections:
| Idx Name          Size      VMA               LMA               File off  Algn
|   0 .text         0000f99f  000000014df91000  000000014df91000  00000400  2**4
|                   CONTENTS, ALLOC, LOAD, READONLY, CODE
|   1 .rodata       00002c40  000000014dfa1000  000000014dfa1000  0000fe00  2**2
|                   CONTENTS, ALLOC, LOAD, READONLY, DATA
|   2 .data         000002d8  000000014dfa4000  000000014dfa4000  00012c00  2**4
|                   CONTENTS, ALLOC, LOAD, DATA
|   3 .sdmagic      00000032  000000014dfa5000  000000014dfa5000  00013000  2**2
|                   CONTENTS, ALLOC, LOAD, READONLY, DATA
|   4 .reloc        00000080  000000014dfa6000  000000014dfa6000  00013200  2**2
|                   CONTENTS, ALLOC, LOAD, READONLY, DATA

Signed-off-by: Jose Quaresma <jose.quaresma@foundries.io>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>