tools: lib: thermal: Correct CFLAGS and LDFLAGS in pkg-config template

tools: lib: thermal: Correct CFLAGS and LDFLAGS in pkg-config template

There are two issues with the current pkg-config template. Firstly, the
-lthermal linker flag is missing. Secondly, the libnl3 include directory
compiler flag references "include" instead of "includedir", which leads to
an unexpanded variable when pkg-config is called.

Add the missing -lthermal flag and correct the libnl3 include directory.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://patch.msgid.link/20251226-libthermal-pkgconfig-v1-1-3406de5ca8ea@bootlin.com