ARM: Remove unused stack and irq config defines

CONFIG_STACKSIZE is not referenced anywhere except on AVR32, but present
in most ARM board config files.

IRQs are only enabled for 1 config, so remove the unused config options
for IRQ and FIQ stack size as well.

Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

include/configs/vision2.h

@@ -176,11 +176,6 @@
 #define CONFIG_CMDLINE_EDITING
 #define CONFIG_SYS_HUSH_PARSER
 
-/*
- * Stack sizes
- */
-#define CONFIG_STACKSIZE		(128 * 1024)	/* regular stack */
-
 /*
  * Physical Memory Map
  */