Add support for R_ARC_NONE relocations.

The R_ARC_NONE relocation is generated when --gc-sections, used by the
compile time linker, removes some sections.  This is completely normal,
and we can see that all other targets (based on random sampling) have
support for R_*_NONE relocations (named for each target).

Handling R_ARC_NONE involves doing nothing with it, which is nice and
easy.

Signed-off-by: Andrew Burgess <andrew.burgess@embecosm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

ldso/ldso/arc/elfinterp.c

@@ -144,6 +144,8 @@ _dl_do_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
 #endif
 
 	switch (reloc_type) {
+	case R_ARC_NONE:
+		break;
 	case R_ARC_32:
 		*reloc_addr += symbol_addr + rpnt->r_addend;
 		break;
@@ -202,6 +204,8 @@ _dl_do_lazy_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
 #endif
 
 	switch (reloc_type) {
+	case R_ARC_NONE:
+		break;
 	case R_ARC_JMP_SLOT:
 		*reloc_addr += tpnt->loadaddr;
 		break;