avr32: Add simple SRAM allocator

Add SRAM allocator for avr32, which is just a thin wrapper around
genalloc.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index a5793c1..e8ee5fa 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -88,6 +88,7 @@
 	select MMU
 	select PERFORMANCE_COUNTERS
 	select HAVE_GPIO_LIB
+	select GENERIC_ALLOCATOR
 
 #
 # CPU types