shell_commands: gnrc_netif: only include LoRA options when LoRA PHY is present

[benpicco]

Contribution description

If no LoRA module is used, there is no use in compiling in all the config options for LoRA PHYs.

This saves about 1k of .text.

It also slims down the switch case in _print_netopt.
Right now, adding only one more entry there will cause an error on AVR:

RIOT/sys/shell/commands/sc_gnrc_netif.c:279:(.text._print_netopt+0x32): relocation truncated to fit: R_AVR_7_PCREL against `no symbol'

This is because there are too many cases and local jumps on that platform can only be so far.

Testing procedure

Compile e.g. examples/gnrc_networking for samr21-xpro

Before:

before:
   text    data     bss     dec     hex filename
  91512     196   18724  110432   1af60 /home/benpicco/dev/RIOT/examples/gnrc_networking/bin/samr21-xpro/gnrc_networking.elf

After:

after:
   text    data     bss     dec     hex filename
  90440     196   18724  109360   1ab30 /home/benpicco/dev/RIOT/examples/gnrc_networking/bin/samr21-xpro/gnrc_networking.elf

Examples using the sx127x module should continue to work.

Issues/PRs references

this adapts the idea from #12171 to existing code.

In that PR, drivers will select a pseudomodule to indicate which PHY options they support

[miri64]

Re-queued build, as the PR is still under discussion.

[miri64]

LGTM now. Let's see, what the LoRA crowd says to this.

Mh... thought re-requesting my review would work. Oh well, then I dismiss it formally

[miri64]

(IMHO this PR can be squashed)

[jia200x]

LGTM. I will test it now on real hardware

[jia200x]

Tested on hardware (samr21-xpro and b-l072z-lrwan1). LoRa options are shown only in the b-l072z-lrwan1 (equipped with a LoRa radio). So it works

[jia200x]

ACK

[jia200x]

...& GO

[benpicco]

Thank you both for the fast review & test!