configure --with-drivers=X does not require its dependencies

[jimklimov]

As raised in #1017:

It seems that configure script does not really know or care about the ever-changing population of drivers, and is geared to enable/disable whole categories (e.g. with/without modbus) so did not require to have libmodbus as a dependency for that particular enabled driver - just opted to use one if available.

We've just bought a UPS2000-A-1KTTS. I'm not very familiar with building C
code, i had some issues. (fresh master 88e8a83)
Linux mgmt01 4.4.0-210-generic #242
#242-Ubuntu SMP Fri Apr 16
09:57:56 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Ubuntu 16.04 (yeah, old, currently under replacement)
config: ./configure --with-user=ups --with-group=nut --with-usb
--with-drivers=huawei-ups2000
i'm not sure if it's a bug, but configure won't complain about missing
modbus lib, but the make will fail. apt-get install libmodbus-dev is needed.

Originally posted by @jimklimov in #1017 (comment)