m68k: Fix invalid .section syntax

gas supports several different forms for .section for ELF targets,
including:
    .section NAME [, "FLAGS"[, @TYPE[,FLAG_SPECIFIC_ARGUMENTS]]]
and:
    .section "NAME"[, #FLAGS...]

In several places we use a mix of these two forms:
    .section NAME, #FLAGS...

A current development snapshot of binutils (2.40.50.20230611) treats
this mixed syntax as an error.

Change to consistently use:
    .section NAME, "FLAGS"
as is used elsewhere in the kernel.

Link: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=m68k&ver=6.4%7Erc6-1%7Eexp1&stamp=1686907300&raw=1
Signed-off-by: Ben Hutchings <benh@debian.org>
Tested-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Link: https://lore.kernel.org/r/ZIyBaueWT9jnTwRC@decadent.org.uk
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/fpsp040/skeleton.S

@@ -499,13 +499,13 @@ in_ea:
 	dbf	%d0,morein
 	rts
 
-	.section .fixup,#alloc,#execinstr
+	.section .fixup,"ax"
 	.even
 1:
 	jbsr	fpsp040_die
 	jbra	.Lnotkern
 
-	.section __ex_table,#alloc
+	.section __ex_table,"a"
 	.align	4
 
 	.long	in_ea,1b

arch/m68k/ifpsp060/os.S

@@ -379,11 +379,11 @@ _060_real_access:
 
 
 | Execption handling for movs access to illegal memory
-	.section .fixup,#alloc,#execinstr
+	.section .fixup,"ax"
 	.even
 1:	moveq		#-1,%d1
 	rts
-.section __ex_table,#alloc
+.section __ex_table,"a"
 	.align 4
 	.long	dmrbuae,1b
 	.long	dmrwuae,1b

arch/m68k/kernel/relocate_kernel.S

@@ -26,7 +26,7 @@ ENTRY(relocate_new_kernel)
 	lea %pc@(.Lcopy),%a4
 2:	addl #0x00000000,%a4		/* virt_to_phys() */
 
-	.section ".m68k_fixup","aw"
+	.section .m68k_fixup,"aw"
 	.long M68K_FIXUP_MEMOFFSET, 2b+2
 	.previous
 
@@ -49,7 +49,7 @@ ENTRY(relocate_new_kernel)
 	lea %pc@(.Lcont040),%a4
 5:	addl #0x00000000,%a4		/* virt_to_phys() */
 
-	.section ".m68k_fixup","aw"
+	.section .m68k_fixup,"aw"
 	.long M68K_FIXUP_MEMOFFSET, 5b+2
 	.previous