In some cases, like when building a Snap application that uses
amdgpu.ids file isn't directly available at the
compiling place, but inside a mounted folder. This forces each
application to link/bind the file from the current place
(usually at $SNAP/gnome-platform/usr/share/libdrm/amdgpu.ids)
into the original path (usually at /usr/share/libdrm/amdgpu.ids),
which is cumbersome.
This patch allows to set an environment variable, called AMDGPU_ASIC_ID_TABLE_PATH, where the file will be also searched if it isn't located in the default, meson-configured, path.