configure: Also test for new "check" option
When configure was called without any --enable-... parameters, the HAVE_DRIVERS
define would be undefined, leading to the driver list being empty:
https://sigrok.org/gitweb/?p=libsigrok.git;a=blob;f=configure.ac;h=
f846fcdc12171bb487596bf92e398d197a6b74dc;hb=HEAD#l304
https://sigrok.org/gitweb/?p=libsigrok.git;a=blob;f=src/drivers.c;h=
6dc2c55cbd18785813186a5e814d0a7d020d1583;hb=HEAD#l50
This was masked when configure is called with --enable-all-drivers as this
parameter is counted as an enabled driver (even though it technically isn't).