MIPS: Enable some missed configs in loongson3_defconfig to support bpftrace

bpftrace is a high-level tracing language for Linux enhanced Berkeley
Packet Filter (eBPF) available in recent Linux kernels (4.x). bpftrace
uses LLVM as a backend to compile scripts to BPF-bytecode and makes use
of BCC for interacting with the Linux BPF system, as well as existing
Linux tracing capabilities: kernel dynamic tracing (kprobes), user-level
dynamic tracing (uprobes), and tracepoints.

According to Linux Kernel Requirements in bpftrace/INSTALL.md [1], the
kernel needs to be built with the following options:

CONFIG_BPF=y
CONFIG_BPF_SYSCALL=y
CONFIG_BPF_JIT=y
CONFIG_HAVE_EBPF_JIT=y
CONFIG_BPF_EVENTS=y
CONFIG_FTRACE_SYSCALLS=y
CONFIG_FUNCTION_TRACER=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_DYNAMIC_FTRACE=y
CONFIG_HAVE_KPROBES=y
CONFIG_KPROBES=y
CONFIG_KPROBE_EVENTS=y
CONFIG_ARCH_SUPPORTS_UPROBES=y
CONFIG_UPROBES=y
CONFIG_UPROBE_EVENTS=y
CONFIG_DEBUG_FS=y

So enable some missed configs in loongson3_defconfig to make sure
the above configs are set after make loongson3_defconfig.

[1] https://github.com/iovisor/bpftrace/blob/master/INSTALL.mdSigned-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/configs/loongson3_defconfig

@@ -26,6 +26,7 @@ CONFIG_SCHED_AUTOGROUP=y
 CONFIG_SYSFS_DEPRECATED=y
 CONFIG_RELAY=y
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_BPF_SYSCALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 CONFIG_MACH_LOONGSON64=y
@@ -39,6 +40,7 @@ CONFIG_MIPS32_O32=y
 CONFIG_MIPS32_N32=y
 CONFIG_VIRTUALIZATION=y
 CONFIG_KVM=m
+CONFIG_KPROBES=y
 CONFIG_MODULES=y
 CONFIG_MODULE_FORCE_LOAD=y
 CONFIG_MODULE_UNLOAD=y
@@ -128,6 +130,7 @@ CONFIG_L2TP=m
 CONFIG_BRIDGE=m
 CONFIG_VSOCKETS=m
 CONFIG_VIRTIO_VSOCKETS=m
+CONFIG_BPF_JIT=y
 CONFIG_CFG80211=m
 CONFIG_CFG80211_WEXT=y
 CONFIG_MAC80211=m
@@ -404,8 +407,10 @@ CONFIG_CRYPTO_DEFLATE=m
 CONFIG_PRINTK_TIME=y
 CONFIG_STRIP_ASM_SYMS=y
 CONFIG_MAGIC_SYSRQ=y
+CONFIG_DEBUG_FS=y
 # CONFIG_SCHED_DEBUG is not set
 # CONFIG_DEBUG_PREEMPT is not set
-# CONFIG_FTRACE is not set
+CONFIG_FUNCTION_TRACER=y
+CONFIG_FTRACE_SYSCALLS=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="ieee754=relaxed"