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/plat/imx/common/include/imx8qx_pads.h b/plat/imx/common/include/imx8qx_pads.h
index 0e153bb..5445aa1 100644
--- a/plat/imx/common/include/imx8qx_pads.h
+++ b/plat/imx/common/include/imx8qx_pads.h
@@ -8,8 +8,8 @@
  * Header file used to configure SoC pad list.
  */
 
-#ifndef SC_PADS_H
-#define SC_PADS_H
+#ifndef IMX8QX_PADS_H
+#define IMX8QX_PADS_H
 
 /* Includes */
 
@@ -195,4 +195,4 @@
 #define SC_P_COMP_CTL_GPIO_1V8_3V3_QSPI0B        173	/*  */
 /*@}*/
 
-#endif				/* SC_PADS_H */
+#endif /* IMX8QX_PADS_H */