Add ARM GICv3 driver without support for legacy operation

This patch adds a driver for ARM GICv3 systems that need to run software
stacks where affinity routing is enabled across all privileged exception
levels for both security states. This driver is a partial implementation
of the ARM Generic Interrupt Controller Architecture Specification, GIC
architecture version 3.0 and version 4.0 (ARM IHI 0069A). The driver does
not cater for legacy support of interrupts and asymmetric configurations.

The existing GIC driver has been preserved unchanged. The common code for
GICv2 and GICv3 systems has been refactored into a new file,
`drivers/arm/gic/common/gic_common.c`. The corresponding header is in
`include/drivers/arm/gic_common.h`.

The driver interface is implemented in `drivers/arm/gic/v3/gicv3_main.c`.
The corresponding header is in `include/drivers/arm/gicv3.h`. Helper
functions are implemented in `drivers/arm/gic/v3/arm_gicv3_helpers.c`
and are accessible through the `drivers/arm/gic/v3/gicv3_private.h`
header.

Change-Id: I8c3c834a1d049d05b776b4dcb76b18ccb927444a
diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index 9aea2c9..49efafc 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -88,6 +88,14 @@
 #define ICC_CTLR_EL1    S3_0_C12_C12_4
 #define ICC_CTLR_EL3    S3_6_C12_C12_4
 #define ICC_PMR_EL1     S3_0_C4_C6_0
+#define ICC_IGRPEN1_EL3 S3_6_c12_c12_7
+#define ICC_IGRPEN0_EL1 S3_0_c12_c12_6
+#define ICC_HPPIR0_EL1  S3_0_c12_c8_2
+#define ICC_HPPIR1_EL1  S3_0_c12_c12_2
+#define ICC_IAR0_EL1    S3_0_c12_c8_0
+#define ICC_IAR1_EL1    S3_0_c12_c12_0
+#define ICC_EOIR0_EL1   S3_0_c12_c8_1
+#define ICC_EOIR1_EL1   S3_0_c12_c12_1
 
 /*******************************************************************************
  * Generic timer memory mapped registers & offsets
@@ -122,6 +130,10 @@
 #define ID_AA64PFR0_EL3_SHIFT	12
 #define ID_AA64PFR0_ELX_MASK	0xf
 
+#define ID_AA64PFR0_GIC_SHIFT	24
+#define ID_AA64PFR0_GIC_WIDTH	4
+#define ID_AA64PFR0_GIC_MASK	((1 << ID_AA64PFR0_GIC_WIDTH) - 1)
+
 /* ID_PFR1_EL1 definitions */
 #define ID_PFR1_VIRTEXT_SHIFT	12
 #define ID_PFR1_VIRTEXT_MASK	0xf