meta-toolchain: Improve layout

* Switch from /usr/local/poky to /opt/poky
* Use a sysroots directory for both the "native" sdk binaries and the target
* Drop the meta-toolchain extras packages. These are replaced with packaged-staging.
* Change the nativesdk layout to match our usual filesystem layout
* Clean up various hardcoded prefix references

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

meta/classes/cross-canadian.bbclass

@@ -44,9 +44,9 @@ target_prefix := "${prefix}"
 target_exec_prefix := "${exec_prefix}"
 
 # Change to place files in SDKPATH
-prefix = "${SDKPATH}"
-exec_prefix = "${SDKPATH}"
-base_prefix = "${SDKPATH}"
+base_prefix = "${SDKPATHNATIVE}"
+prefix = "${SDKPATHNATIVE}${prefix_nativesdk}"
+exec_prefix = "${SDKPATHNATIVE}${prefix_nativesdk}"
 
 FILES_${PN} = "${prefix}"
 FILES_${PN}-dbg += "${prefix}/.debug \
@@ -56,5 +56,5 @@ FILES_${PN}-dbg += "${prefix}/.debug \
 export PKG_CONFIG_DIR = "${STAGING_DIR_HOST}${layout_libdir}/pkgconfig"
 export PKG_CONFIG_SYSROOT_DIR = "${STAGING_DIR_HOST}"
 
-# Cross-canadian packages need to pull in nativesdk so's, sorry for ugliness
+# Cross-canadian packages need to pull in nativesdk dynamic libs
 SHLIBSDIR = "${STAGING_DIR}/${SDK_ARCH}-nativesdk-pokysdk-${BUILD_OS}/shlibs"

meta/classes/nativesdk.bbclass

@@ -37,9 +37,9 @@ CXXFLAGS = "${BUILDSDK_CFLAGS}"
 LDFLAGS = "${BUILDSDK_LDFLAGS}"
 
 # Change to place files in SDKPATH
-prefix = "${SDKPATH}"
-exec_prefix = "${SDKPATH}"
-base_prefix = "${SDKPATH}"
+base_prefix = "${SDKPATHNATIVE}"
+prefix = "${SDKPATHNATIVE}${prefix_nativesdk}"
+exec_prefix = "${SDKPATHNATIVE}${prefix_nativesdk}"
 
 FILES_${PN} += "${prefix}"
 FILES_${PN}-dbg += "${prefix}/.debug \