cpu_linux: Ignore non-cpu info on /proc/cpuinfo

[rene]

Some arm64 devices might have additional lines on /proc/cpuinfo containing additional information in a non <field>: <value> format, so these lines must be ignored.

Example of a /proc/cpuinfo from a Qualcomm device:

processor : 7
BogoMIPS : 38.40
Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x51
CPU architecture: 8
CPU variant : 0xa
CPU part : 0x800
CPU revision : 2

Qualcomm Technologies, Inc QCM6125

The following crash is observed in this device:

2026-02-06T13:31:44.317846806Z;pillar.out;2026-02-06T13:31:44,305770920+00:00 waited 3 for /run/zedagent.touch
2026-02-06T13:31:44.332954097Z;pillar;panic: runtime error: index out of range [1] with length 1
2026-02-06T13:31:44.33298316Z;pillar;
2026-02-06T13:31:44.333068472Z;pillar;goroutine 27 [running]:
2026-02-06T13:31:44.333073837Z;pillar;github.com/zededa/ghw/pkg/cpu.logicalProcessorsFromProcCPUInfo(0x4000568870)
2026-02-06T13:31:44.333104201Z;pillar;	/pillar/vendor/github.com/zededa/ghw/pkg/cpu/cpu_linux.go:380 +0x32c
2026-02-06T13:31:44.346752743Z;pillar;github.com/zededa/ghw/pkg/cpu.processorsGet(0x4000568870)
2026-02-06T13:31:44.346811649Z;pillar;	/pillar/vendor/github.com/zededa/ghw/pkg/cpu/cpu_linux.go:47 +0x34
2026-02-06T13:31:44.346893837Z;pillar;github.com/zededa/ghw/pkg/cpu.(*Info).load(0x40018dd560, 0x11c6a8c?)
2026-02-06T13:31:44.346899253Z;pillar;	/pillar/vendor/github.com/zededa/ghw/pkg/cpu/cpu_linux.go:30 +0x24
2026-02-06T13:31:44.360680972Z;pillar;github.com/zededa/ghw/pkg/cpu.New({0x40017df9b8, 0x1, 0x40018dd4d0?})
2026-02-06T13:31:44.360708003Z;pillar;	/pillar/vendor/github.com/zededa/ghw/pkg/cpu/cpu.go:147 +0x7c
2026-02-06T13:31:44.360793368Z;pillar;github.com/lf-edge/eve/pkg/pillar/hardware.getCPUInfo()
2026-02-06T13:31:44.360798212Z;pillar;	/pillar/hardware/inventory.go:410 +0x54
2026-02-06T13:31:44.360825347Z;pillar;github.com/lf-edge/eve/pkg/pillar/hardware.GetInventoryInfo(0x40005c56f8)
2026-02-06T13:31:44.360829983Z;pillar;	/pillar/hardware/inventory.go:38 +0x3ac
2026-02-06T13:31:44.365867274Z;pillar;github.com/lf-edge/eve/pkg/pillar/cmd/zedagent.Run(0x40008e3a40, 0x4000860e00?, 0x40005c56f8?, {0x4cb5880, 0x0, 0x0}, {0x0, 0x0})
2026-02-06T13:31:44.365898055Z;pillar;	/pillar/cmd/zedagent/zedagent.go:414 +0x464
2026-02-06T13:31:44.36700342Z;pillar;main.startAgentAndDone({0x2b13708?, 0x0?}, {0x40008e8378, 0x8}, 0x0?, 0x484218?, 0x4000081d50?, {0x4cb5880?, 0x400079b0e0?, 0x0?})
2026-02-06T13:31:44.367937847Z;pillar;	/pillar/zedbox/zedbox.go:249 +0x58
2026-02-06T13:31:44.368051858Z;pillar;created by main.handleService in goroutine 1
2026-02-06T13:31:44.36816368Z;pillar;	/pillar/zedbox/zedbox.go:238 +0x2b8
2026-02-06T13:31:44.451876858Z;pillar.out;2026-02-06T13:31:44,450270920+00:00 waited 0 for /run/ledmanager.touch
2026-02-06T13:31:44.53225342Z;newlogd.out;{"file":"/newlog/vendor/github.com/lf-edge/eve/pkg/pillar/pubsub/socketdriver/subscribe.go:278","func":"github.com/lf-edge/eve/pkg/pillar/pubsub/socketdriver.(*Subscriber).read","level":"error","msg":"connectAndRead(zedagent/ConfigItemValueMap): sock read failed EOF","pid":2561,"source":"newlogd","time":"2026-02-06T13:31:44.531316389Z"}
``