feat(rmm): add support for the 2nd DRAM bank

This patch adds support for RMM granules allocation
in FVP 2nd DRAM 2GB bank at 0x880000000 base address.
For ENABLE_RME = 1 case it also removes "mem=1G"
Linux kernel command line option in fvp-base-psci-common.dsti
to allow memory layout discovery from the FVP device tree.
FVP parameter 'bp.dram_size' - size of main memory in gigabytes
documented in docs/components/realm-management-extension.rst
is changed from 2 to 4.

Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
Change-Id: I174da4416ad5a8d41bf0ac89f356dba7c0cd3fe7
diff --git a/fdts/fvp-base-psci-common.dtsi b/fdts/fvp-base-psci-common.dtsi
index 6018f0c..7838fde 100644
--- a/fdts/fvp-base-psci-common.dtsi
+++ b/fdts/fvp-base-psci-common.dtsi
@@ -28,7 +28,7 @@
 	#size-cells = <2>;
 
 #if (ENABLE_RME == 1)
-	chosen { bootargs = "mem=1G console=ttyAMA0 earlycon=pl011,0x1c090000 root=/dev/vda ip=on";};
+	chosen { bootargs = "console=ttyAMA0 earlycon=pl011,0x1c090000 root=/dev/vda ip=on";};
 #else
 	chosen {};
 #endif