AVR32: Remove useless config option "GENERIC_BUST_SPINLOCK".

Remove the clearly useless config option GENERIC_BUST_SPINLOCK, which
is not used anywhere in the tree.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 50fee54..3ec7658 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -57,9 +57,6 @@
 	bool
 	default n
 
-config GENERIC_BUST_SPINLOCK
-	bool
-
 config GENERIC_HWEIGHT
 	bool
 	default y