fix "Procedure is not pure assembler"

Misra C reqires assembly code should comply with
the rules list below:
  The assembly code's functionality should match the function's
name.If not,pls encapsulate the assembly code and give a suitable
name for describing the functionality.
V1->V2:
    1.remove the dead code
    2.update detail comment

V2->V3:
    1.replace the macro name with upper case.
    2.remove the typedef and rename the struct name
"_descriptor_table_" to "descriptor_table".

Tracked-On: #861
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/debug/dump.c

@@ -243,7 +243,7 @@ void asm_assert(int32_t line, const char *file, const char *txt)
 	show_host_call_trace(rsp, rbp, pcpu_id);
 	dump_guest_context(pcpu_id);
 	do {
-		asm volatile ("pause" ::: "memory");
+		pause_cpu();
 	} while (1);
 }