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: NFrançois Ozog <francois.ozog@linaro.org>
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>

arch/arm/Kconfig

@@ -938,6 +938,7 @@ config ARCH_QEMU
 	select OF_CONTROL
 	select PL01X_SERIAL
 	imply CMD_DM
+	imply DM_RNG
 	imply DM_RTC
 	imply RTC_PL031