arm, arm926ejs: Add option CONFIG_SYS_EXCEPTION_VECTORS_HIGH

The V bit of the c1 register of CP15 should not be cleared on DA850
SoCs since they have no valid memory at 0x00000000. This patch
introduces a configuration option CONFIG_SYS_EXCEPTION_VECTORS_HIGH
that allows setting the correct value for the V bit.

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Reported-by: Sughosh Ganu <urwithsughosh@gmail.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@ti.com>
Cc: Sughosh Ganu <urwithsughosh@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
diff --git a/include/configs/hawkboard.h b/include/configs/hawkboard.h
index 21f7b9b..c310c73 100644
--- a/include/configs/hawkboard.h
+++ b/include/configs/hawkboard.h
@@ -35,6 +35,7 @@
 #define CONFIG_ARM926EJS		/* arm926ejs CPU core */
 #define CONFIG_SOC_DA8XX		/* TI DA8xx SoC */
 #define CONFIG_SOC_DA850		/* TI DA850 SoC */
+#define CONFIG_SYS_EXCEPTION_VECTORS_HIGH
 #define CONFIG_SYS_CLK_FREQ		clk_get(DAVINCI_ARM_CLKID)
 #define CONFIG_SYS_OSCIN_FREQ		24000000
 #define CONFIG_SYS_TIMERBASE		DAVINCI_TIMER0_BASE