Pass --enable-shared and --with-hscolour to ghc-cabal configure

It tried to do this already, but the make variable name was wrong.

rules/build-package-data.mk

@@ -13,11 +13,11 @@
 define build-package-data # args: $1 = dir, $2 = distdir
 
 ifeq "$(BuildSharedLibs)" "YES"
-$1_$2_CONFIGURE_FLAGS += --enable-shared
+$1_$2_CONFIGURE_OPTS += --enable-shared
 endif
 
 ifeq "$(HSCOLOUR_SRCS)" "YES"
-$1_$2_CONFIGURE_FLAGS += --with-hscolour="$$(HSCOLOUR)"
+$1_$2_CONFIGURE_OPTS += --with-hscolour="$$(HSCOLOUR)"
 endif
 
 # This rule configures the package, generates the package-data.mk file