meson: modify meson definitions for gl_generic module

meson: modify meson definitions for gl_generic module

in tizen environment, gl_generic module can't be dynamically loadded,
because some symbols are not linked.

so this patch modify meson definitions to build gl_generic
as static linked library . it's workaround.

and also there are some sources that exist on tizen only. this patch appends them.

@tizen_only

Change-Id: I50a5ee74a684a93a102698cdb276e03e0b1d8134