s390/module: enable generic CPU feature modalias using s390 ELF hwcaps

Add support for the generic CPU feature modalias implementation that wires
up optional CPU features to udev-based module autoprobing.

The <asm/cpufeature.h> file provides definitions to map CPU features to
s390 ELF hardware capabilities.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index ca070d2..85a1d47 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -76,7 +76,7 @@
 unsigned int console_irq = -1;
 EXPORT_SYMBOL(console_irq);
 
-unsigned long elf_hwcap = 0;
+unsigned long elf_hwcap __read_mostly = 0;
 char elf_platform[ELF_PLATFORM_SIZE];
 
 int __initdata memory_end_set;