configure: icc: Drop nonsense adding of cpuflags to LDFLAGS

This fixes many icc warnings when not setting the CPU type.

configure

@@ -3716,8 +3716,6 @@ if enabled icc; then
     # 11030: Warning unknown option --as-needed
     # 10156: ignoring option '-export'; no argument required
     check_ldflags -wd10156,11030
-    # Allow to compile with optimizations
-    check_ldflags -march=$cpu
     # icc 11.0 and 11.1 work with ebp_available, but don't pass the test
     enable ebp_available
     if enabled x86_32; then