ARM: shmobile: smp: Enforce shmobile_smp_* alignment

When the addresses of the shmobile_smp_mpidr, shmobile_smp_fn, and
shmobile_smp_arg variables are not multiples of 4 bytes, secondary CPU
bring-up fails:

    smp: Bringing up secondary CPUs ...
    CPU1: failed to come online
    CPU2: failed to come online
    CPU3: failed to come online
    smp: Brought up 1 node, 1 CPU

Fix this by adding the missing alignment directive.

Fixes: 4e960f52fce16a3b ("ARM: shmobile: Move shmobile_smp_{mpidr, fn, arg}[] from .text to .bss")
Closes: https://lore.kernel.org/r/CAMuHMdU=QR-JLgEHKWpsr6SbaZRc-Hz9r91JfpP8c3n2G-OjqA@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/c499234d559a0d95ad9472883e46077311051cd8.1741612208.git.geert+renesas@glider.be
Cc: stable@vger.kernel.org
diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index a956b48..2bc7e73 100644
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -136,6 +136,7 @@
 	.long	shmobile_smp_arg - 1b
 
 	.bss
+	.align	2
 	.globl	shmobile_smp_mpidr
 shmobile_smp_mpidr:
 	.space	NR_CPUS * 4