ARCv3: export __clear_user symbol to dynamically loaded modules

Fix build error for modules used the clear_user macro.
Symbol __clear_user comes to modules from the clear_user macro.
Don't export symbols for raw_copy_from_user and raw_copy_to_user, as
they are not a part of public API for modules and for ARC defined
__get_user_fn,__put_user_fn macros without use of raw_copy_from_user
and raw_copy_to_user.

Signed-off-by: Pavel Kozlov <pavel.kozlov@synopsys.com>

Author: pavelvkozlov

arch/arc/lib/uaccess.S

@@ -4,6 +4,7 @@
  *   ASSUMES unaligned access
  */
 
+#include <asm-generic/export.h>
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
@@ -124,6 +125,7 @@ ENTRY_CFI(__clear_user)
 	sub    r0, r8, r0
 
 END_CFI(__clear_user)
+EXPORT_SYMBOL(__clear_user)
 
 ; Note that .fixup section is missing and that is not an omission
 ;