dmaengine: at_xdmac: prefer usage of readl/writel_relaxed

_relaxed version of readl and writel are not implemented on all
architecture so COMPILE_TEST has to be removed in order to not cause
some build failures.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 607271a..8b6fb0f 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -109,7 +109,7 @@
 
 config AT_XDMAC
 	tristate "Atmel XDMA support"
-	depends on (ARCH_AT91 || COMPILE_TEST)
+	depends on ARCH_AT91
 	select DMA_ENGINE
 	help
 	  Support the Atmel XDMA controller.