modules: Add missing entry for __ex_table

The entry for __ex_table was missing, which may make __ex_table
become 1- or 2-byte aligned in modules.
Add the entry to ensure it gets 32-bit aligned.

As per unaligned-memory-access [0] "unaligned memory accesses [...]
will not work correctly on certain platforms and will cause performance
problems on others", so fix this.

Signed-off-by: Helge Deller <[email protected]>
[mcgrof: added unaligned-memory-access justification]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/core-api/unaligned-memory-access.rst # [0]
Signed-off-by: Luis Chamberlain <[email protected]>

Author: hdeller

scripts/module.lds.S

@@ -29,6 +29,7 @@ SECTIONS {
 	.altinstructions	0 : ALIGN(8) { KEEP(*(.altinstructions)) }
 	__bug_table		0 : ALIGN(8) { KEEP(*(__bug_table)) }
 	__jump_table		0 : ALIGN(8) { KEEP(*(__jump_table)) }
+	__ex_table		0 : ALIGN(4) { KEEP(*(__ex_table)) }
 
 	__patchable_function_entries : { *(__patchable_function_entries) }