package/pkg-meson: add cmake dependency support

Meson dependencies and variables can be provided by cmake similar to
how they can be provided by pkgconfig, for this to work we need to
ensure that cmake_prefix_path is set for both cross and native
targets along with the cmake binary path.

See:
https://mesonbuild.com/Dependencies.html#cmake
https://mesonbuild.com/Dependencies.html#arbitrary-variables-from-dependencies-that-can-be-found-multiple-ways
https://mesonbuild.com/Machine-files.html#meson-builtin-options

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/pkg-meson.mk

@@ -79,6 +79,7 @@ define PKG_MESON_CROSSCONFIG_SED
         -e "s%@TARGET_CFLAGS@%$(call make-sq-comma-list,$($(strip $(1))))%g" \
         -e "s%@TARGET_LDFLAGS@%$(call make-sq-comma-list,$($(strip $(3))))%g" \
         -e "s%@TARGET_CXXFLAGS@%$(call make-sq-comma-list,$($(strip $(2))))%g" \
+        -e "s%@BR2_CMAKE@%$(BR2_CMAKE)%g" \
         -e "s%@PKGCONF_HOST_BINARY@%$(HOST_DIR)/bin/pkgconf%g" \
         -e "s%@STAGING_DIR@%$(STAGING_DIR)%g" \
         -e "s%@STATIC@%$(if $(BR2_STATIC_LIBS),true,false)%g" \
@@ -136,6 +137,7 @@ define $(2)_CONFIGURE_CMDS
 		-Db_pie=false \
 		-Dstrip=false \
 		-Dbuild.pkg_config_path=$$(HOST_DIR)/lib/pkgconfig \
+		-Dbuild.cmake_prefix_path=$$(HOST_DIR)/lib/cmake \
 		$$($$(PKG)_CONF_OPTS) \
 		$$($$(PKG)_SRCDIR) $$($$(PKG)_SRCDIR)/build
 endef

support/misc/cross-compilation.conf.in

@@ -8,6 +8,7 @@ c = '@TARGET_CC@'
 cpp = '@TARGET_CXX@'
 ar = '@TARGET_AR@'
 strip = '@TARGET_STRIP@'
+cmake = '@BR2_CMAKE@'
 pkgconfig = '@PKGCONF_HOST_BINARY@'
 g-ir-compiler = '@STAGING_DIR@/usr/bin/g-ir-compiler'
 g-ir-scanner = '@STAGING_DIR@/usr/bin/g-ir-scanner'
@@ -18,6 +19,7 @@ c_link_args = [@TARGET_LDFLAGS@]
 cpp_args = [@TARGET_CXXFLAGS@]
 cpp_link_args = [@TARGET_LDFLAGS@]
 wrap_mode = 'nodownload'
+cmake_prefix_path = '@STAGING_DIR@/usr/lib/cmake'
 
 [properties]
 needs_exe_wrapper = true