Standardise header guards across codebase

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/drivers/arm/gic/common/gic_common_private.h b/drivers/arm/gic/common/gic_common_private.h
index fa34e47..9d9e8c7 100644
--- a/drivers/arm/gic/common/gic_common_private.h
+++ b/drivers/arm/gic/common/gic_common_private.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef GIC_COMMON_PRIVATE_H_
-#define GIC_COMMON_PRIVATE_H_
+#ifndef GIC_COMMON_PRIVATE_H
+#define GIC_COMMON_PRIVATE_H
 
 #include <gic_common.h>
 #include <mmio.h>
@@ -85,4 +85,4 @@
 void gicd_set_ipriorityr(uintptr_t base, unsigned int id, unsigned int pri);
 void gicd_set_icfgr(uintptr_t base, unsigned int id, unsigned int cfg);
 
-#endif /* GIC_COMMON_PRIVATE_H_ */
+#endif /* GIC_COMMON_PRIVATE_H */
diff --git a/drivers/arm/gic/v2/gicv2_private.h b/drivers/arm/gic/v2/gicv2_private.h
index 1eb6d9d..ccfad78 100644
--- a/drivers/arm/gic/v2/gicv2_private.h
+++ b/drivers/arm/gic/v2/gicv2_private.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __GICV2_PRIVATE_H__
-#define __GICV2_PRIVATE_H__
+#ifndef GICV2_PRIVATE_H
+#define GICV2_PRIVATE_H
 
 #include <gicv2.h>
 #include <mmio.h>
@@ -146,4 +146,4 @@
 	mmio_write_32(base + GICC_DIR, val);
 }
 
-#endif /* __GICV2_PRIVATE_H__ */
+#endif /* GICV2_PRIVATE_H */
diff --git a/drivers/arm/gic/v3/gicv3_private.h b/drivers/arm/gic/v3/gicv3_private.h
index 85231ad..188e711 100644
--- a/drivers/arm/gic/v3/gicv3_private.h
+++ b/drivers/arm/gic/v3/gicv3_private.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __GICV3_PRIVATE_H__
-#define __GICV3_PRIVATE_H__
+#ifndef GICV3_PRIVATE_H
+#define GICV3_PRIVATE_H
 
 #include <assert.h>
 #include <gic_common.h>
@@ -387,4 +387,4 @@
 }
 
 
-#endif /* __GICV3_PRIVATE_H__ */
+#endif /* GICV3_PRIVATE_H */