tests: enable user mode by default

Many boards do not enable user mode in their default configuration
even though they support it. However for purposes of our unit
testing we really do want it on all the time.

It's not enough to just flip on CONFIG_USERSPACE, the tests largely
assume that CONFIG_APPLICATION_MEMORY and CONFIG_DYNAMIC_OBJECTS
are enabled. Update CONFIG_TEST_USERSPACE to be on by default if
CONFIG_TEST is active, and hang CONFIG_DYNAMIC_OBJECTS on it too.

This problem was not previously detected as qemu_x86 has the
user mode options in its defconfig and it is currently the only
user mode compatible platform which runs in emulation.

Fixes #7692

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

tests/Kconfig

@@ -36,9 +36,11 @@ config COVERAGE
 config TEST_USERSPACE
 	bool "Enable userspace if available"
 	depends on ARCH_HAS_USERSPACE
+	depends on TEST
 	select USERSPACE
 	select APPLICATION_MEMORY
-	default n
+	select DYNAMIC_OBJECTS
+	default y
 	help
 	  This option will help test the userspace mode. This can be enabled
 	  only when CONFIG_HAS_USERSPACE is set.