Add support to indicate size and end of assembly functions

In order for the symbol table in the ELF file to contain the size of
functions written in assembly, it is necessary to report it to the
assembler using the .size directive.

To fulfil the above requirements, this patch introduces an 'endfunc'
macro which contains the .endfunc and .size directives. It also adds
a .func directive to the 'func' assembler macro.

The .func/.endfunc have been used so the assembler can fail if
endfunc is omitted.

Fixes ARM-Software/tf-issues#295

Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>
diff --git a/plat/common/aarch64/platform_helpers.S b/plat/common/aarch64/platform_helpers.S
index c236fd7..c117449 100644
--- a/plat/common/aarch64/platform_helpers.S
+++ b/plat/common/aarch64/platform_helpers.S
@@ -52,6 +52,7 @@
 	and	x0, x0, #MPIDR_CLUSTER_MASK
 	add	x0, x1, x0, LSR #6
 	ret
+endfunc platform_get_core_pos
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -61,6 +62,7 @@
 func platform_check_mpidr
 	mov	x0, xzr
 	ret
+endfunc platform_check_mpidr
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -69,6 +71,7 @@
 	 */
 func plat_report_exception
 	ret
+endfunc plat_report_exception
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -78,6 +81,7 @@
 func plat_crash_console_init
 	mov	x0, #0
 	ret
+endfunc plat_crash_console_init
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -86,6 +90,7 @@
 	 */
 func plat_crash_console_putc
 	ret
+endfunc plat_crash_console_putc
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -94,6 +99,7 @@
 	 */
 func plat_reset_handler
 	ret
+endfunc plat_reset_handler
 
 	/* -----------------------------------------------------
 	 * Placeholder function which should be redefined by
@@ -103,3 +109,4 @@
 	 */
 func plat_disable_acp
 	ret
+endfunc plat_disable_acp