meson: ipa, proxy: Only build proxies for enabled pipelines

All the IPA proxies are build unconditionally consuming unneeded build
time and disk space on target. Fix this by only building the proxies for
the enabled pipelines.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/ipa/meson.build

@@ -72,6 +72,10 @@ ipa_mojoms = []
 foreach file : ipa_mojom_files
     name = file.split('.')[0]
 
+    if not get_option('pipelines').contains(name)
+        continue
+    endif
+
     # {pipeline}.mojom-module
     mojom = custom_target(file.split('.')[0] + '_mojom_module',
                           input : file,