module.bbclass: Add INSTALL_FW_PATH for out-of-tree modules

This same variable was added to the make line in kernel.bbclass in
0decf1cc1c. With the addition of the
usrmerge feature, out-of-tree modules could use this same variable.

(From OE-Core rev: 1d24d1ac5b9c772d84104396438e5d1308332785)

Signed-off-by: Wes Lindauer <wesley.lindauer@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/module.bbclass

@@ -48,6 +48,7 @@ module_do_compile() {
 module_do_install() {
 	unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
 	oe_runmake DEPMOD=echo MODLIB="${D}${nonarch_base_libdir}/modules/${KERNEL_VERSION}" \
+	           INSTALL_FW_PATH="${D}${nonarch_base_libdir}/firmware" \
 	           CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
 	           O=${STAGING_KERNEL_BUILDDIR} \
 	           ${MODULES_INSTALL_TARGET}