x11/virtualgl: fix build with lld 17

Building x11/virtualgl with lld 17 results in the following link errors:

ld: error: version script assignment of 'global' to symbol 'clCreateContext' failed: symbol not defined

Since the same linker version script is used for all "libvglfaker"
library variants, where only one of the implements the clCreateContext
symbol, suppress errors with lld >= 17 due to this undefined symbol.

PR: 273753
MFH: 2023Q4