tests/tcg/Makefile.target: fix path to config-host.mak

Since moving where the tests are run the path to config-host.mak has
been wrong. This doesn't affect much but things like the time fallback
for CONFIG_DEBUG_TCG and will also get in the way of checking for
PLUGINS support.

Fixes: fc76c56
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

tests/tcg/Makefile.target

@@ -30,7 +30,7 @@
 #
 
 all:
--include ../../config-host.mak
+-include ../../../config-host.mak
 -include ../config-$(TARGET).mak
 
 # for including , in command strings