arm: enable DM_RNG on QEMU by default

The EFI_RNG_PROTOCOL is needed for address randomization in Linux.
We should provide it by default on QEMU.

Reported-by: François Ozog <francois.ozog@linaro.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 7c206ce..b885b9e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -938,6 +938,7 @@
 	select OF_CONTROL
 	select PL01X_SERIAL
 	imply CMD_DM
+	imply DM_RNG
 	imply DM_RTC
 	imply RTC_PL031