`L1CACHE.linesize` is `nothing` on WSL2 Ubuntu making LoopVectorization.jl fail to precompile

Not sure if this is a [VectorizationBase.jl](https://github.com/chriselrod/VectorizationBase.jl), [LoopVectorization.jl](https://github.com/chriselrod/LoopVectorization.jl), or [Hwloc.jl](https://github.com/JuliaParallel/Hwloc.jl) bug.

`L1CACHE.linesize=nothing` on my system:
```
julia> VectorizationBase.L₁CACHE
(size = nothing, depth = nothing, linesize = nothing, associativity = nothing, type = nothing)
```
This causes `LoopVectorization.jl` to fail to precompile.

My system is the WSL2, the Windows Subsystem for Linux 2 running Ubuntu-20.04. The `/proc/cpuinfo` appears normal (happy to post on request), CPU is `Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz`.

Some more info:
```
julia> VectorizationBase.CACHE_COUNT
(0, 0, 0, 0)

julia> VectorizationBase.COUNTS
Dict{Symbol,Int64} with 19 entries:
:Package => 1
:Error => 0
:PU => 16
:OS_Device => 0
:L5Cache => 0
:L4Cache => 0
:I1Cache => 0
:L3Cache => 0
:Core => 8
:Machine => 1
:I3Cache => 0
:PCI_Device => 0
:L2Cache => 0
:NUMANode => 0
:Bridge => 0
:Group => 0
:Misc => 0
:L1Cache => 0
:I2Cache => 0

julia> VectorizationBase.TOPOLOGY
D0: L0 P0 Machine
D1: L0 P0 Package
D2: L0 P0 Core
D3: L0 P0 PU
D3: L1 P1 PU
D2: L1 P1 Core
D3: L2 P2 PU
D3: L3 P3 PU
D2: L2 P2 Core
D3: L4 P4 PU
D3: L5 P5 PU
D2: L3 P3 Core
D3: L6 P6 PU
D3: L7 P7 PU
D2: L4 P4 Core
D3: L8 P8 PU
D3: L9 P9 PU
D2: L5 P5 Core
D3: L10 P10 PU
D3: L11 P11 PU
D2: L6 P6 Core
D3: L12 P12 PU
D3: L13 P13 PU
D2: L7 P7 Core
D3: L14 P14 PU
D3: L15 P15 PU

```