remove all references to .dynsym

Discard all .dynsym sections from linker scripts
Remove all __dynsym_start definitions from linker scripts
Remove all __dynsym_start references from the codebase

Note: this touches include/asm-generic/sections.h, which
is not ARM-specific, but actual uses of __dynsym_start
are only in ARM, so this patch can safely go through
the ARM repository.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Tested-by: Lubomir Popov <lpopov@mm-sol.com>
Tested-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
diff --git a/board/dvlhost/u-boot.lds b/board/dvlhost/u-boot.lds
index 6d4b187..ecd9efe 100644
--- a/board/dvlhost/u-boot.lds
+++ b/board/dvlhost/u-boot.lds
@@ -70,11 +70,6 @@
 		__rel_dyn_end = .;
 	}
 
-	.dynsym : {
-		__dynsym_start = .;
-		*(.dynsym)
-	}
-
 	_end = .;
 
 /*
@@ -96,6 +91,7 @@
 		KEEP(*(.__bss_end));
 	}
 
+	/DISCARD/ : { *(.dynsym) }
 	/DISCARD/ : { *(.dynstr*) }
 	/DISCARD/ : { *(.dynamic*) }
 	/DISCARD/ : { *(.plt*) }