testing: move arm system tests into their own folder

Prepare for expanding the arm system tests by cleaning up the test
directory.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231120150833.2552739-11-alex.bennee@linaro.org>

tests/tcg/arm/Makefile.softmmu-target

@@ -3,7 +3,7 @@
 # ARM SoftMMU tests - included from tests/tcg/Makefile
 #
 
-ARM_SRC=$(SRC_PATH)/tests/tcg/arm
+ARM_SRC=$(SRC_PATH)/tests/tcg/arm/system
 
 # Set search path for all sources
 VPATH 		+= $(ARM_SRC)
@@ -12,7 +12,6 @@ ARM_TESTS=test-armv6m-undef
 
 TESTS += $(ARM_TESTS)
 
-CFLAGS+=-Wl,--build-id=none -x assembler-with-cpp
 LDFLAGS+=-nostdlib -N -static
 
 %: %.S %.ld
@@ -20,7 +19,7 @@ LDFLAGS+=-nostdlib -N -static
 
 # Specific Test Rules
 
-test-armv6m-undef: EXTRA_CFLAGS+=-mcpu=cortex-m0 -mfloat-abi=soft
+test-armv6m-undef: EXTRA_CFLAGS+=-mcpu=cortex-m0 -mfloat-abi=soft -Wl,--build-id=none -x assembler-with-cpp
 
 run-test-armv6m-undef: QEMU_OPTS+=-semihosting -M microbit -kernel