perf: fix build on mips

perf: fix build on mips

Building perf on mips/malta fails on intel-pt-decoder due to a header issue
previously seen in f434643857 ("perf: fix build on PowerPC"):

In file included from util/intel-pt-decoder/intel-pt-insn-decoder.c:12:
util/intel-pt-decoder/../../../arch/x86/include/asm/insn.h: In function 'insn_field_set':
util/intel-pt-decoder/../../../arch/x86/include/asm/insn.h:56:21: error: implicit declaration of function '__cpu_to_le32'; did you mean 'cpu_to_le32'? [-Wimplicit-function-declaration]
   56 |         p->little = __cpu_to_le32(v);
      |                     ^~~~~~~~~~~~~
      |                     cpu_to_le32
util/intel-pt-decoder/../../../arch/x86/include/asm/insn.h: In function 'insn_set_byte':
util/intel-pt-decoder/../../../arch/x86/include/asm/insn.h:64:20: error: implicit declaration of function '__le32_to_cpu'; did you mean 'le32_to_cpu'? [-Wimplicit-function-declaration]
   64 |         p->value = __le32_to_cpu(p->little);
      |                    ^~~~~~~~~~~~~
      |                    le32_to_cpu

Extend the previous powerpc fix to mips, disabling intel-pt-decoder build.

cc: Stijn Tintel <stijn@linux-ipv6.be>
Signed-off-by: Tony Ambardar <itugrok@yahoo.com>
Link: https://github.com/openwrt/openwrt/pull/19426
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>