[ARM] Remove export of kd_mksound.

This symbol is no longer used in modules.

arch/arm/kernel/armksyms.c

@@ -88,10 +88,6 @@ EXPORT_SYMBOL_ALIAS(kern_fp_enter,fp_enter);
 EXPORT_SYMBOL_ALIAS(fp_printk,printk);
 EXPORT_SYMBOL_ALIAS(fp_send_sig,send_sig);
 
-#ifdef CONFIG_VT
-EXPORT_SYMBOL(kd_mksound);
-#endif
-
 EXPORT_SYMBOL_NOVERS(__do_softirq);
 EXPORT_SYMBOL_NOVERS(__backtrace);