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/marvell/comphy/comphy-cp110.h b/drivers/marvell/comphy/comphy-cp110.h
index 1d7aec8..6eb7fd0 100644
--- a/drivers/marvell/comphy/comphy-cp110.h
+++ b/drivers/marvell/comphy/comphy-cp110.h
@@ -7,8 +7,8 @@
 
 /* Marvell CP110 SoC COMPHY unit driver */
 
-#ifndef _PHY_COMPHY_CP110_H
-#define _PHY_COMPHY_CP110_H
+#ifndef COMPHY_CP110_H
+#define COMPHY_CP110_H
 
 #define SD_ADDR(base, lane)			(base + 0x1000 * lane)
 #define HPIPE_ADDR(base, lane)			(SD_ADDR(base, lane) + 0x800)
@@ -862,5 +862,4 @@
 /* General defines */
 #define PLL_LOCK_TIMEOUT			15000
 
-#endif /* _PHY_COMPHY_CP110_H */
-
+#endif /* COMPHY_CP110_H */