cpukit mips: Address unused parameter warnings

Add "(void) param;" annotation to address unused parameter warnings.
Found with GCC's warning -Wunused-parameter.

cpukit/libdl/rtl-mdreloc-mips.c

@@ -52,6 +52,9 @@ uint32_t
 rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj,
                              const Elf_Shdr*      shdr)
 {
+  (void) obj;
+  (void) shdr;
+
   return 0;
 }
 
@@ -90,6 +93,8 @@ rtems_rtl_elf_arch_section_free (const rtems_rtl_obj* obj,
 bool
 rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
 {
+  (void) type;
+
   return true;
 }
 
@@ -185,6 +190,8 @@ rtems_rtl_elf_relocate_rel (rtems_rtl_obj*            obj,
                             const Elf_Byte            syminfo,
                             const Elf_Word            symvalue)
 {
+  (void) symname;
+
   Elf_Addr *where;
   Elf_Word tmp;
   Elf_Word addend = (Elf_Word)0;

cpukit/score/cpu/mips/cpu.c

@@ -194,6 +194,9 @@ void _CPU_Context_Initialize(
   void             *tls_area
 )
 {
+  (void) is_fp;
+  (void) tls_area;
+
   uintptr_t             stack_tmp;
   __MIPS_REGISTER_TYPE  intlvl = new_level & 0xff;
   __MIPS_REGISTER_TYPE  c0_sr;
@@ -236,6 +239,8 @@ void _CPU_Context_Initialize(
 
 void *_CPU_Thread_Idle_body( uintptr_t ignored )
 {
+  (void) ignored;
+
 #if (__mips == 3) || (__mips == 32)
    for( ; ; )
      __asm__ volatile("wait"); /* use wait to enter low power mode */