Unify cpp files to one

Unify cpp files to one

Merge below cpp files to device_haltests.cpp
gtest_hal_battery.cpp
gtest_hal_cpu.cpp
gtest_hal_display.cpp
gtest_hal_extcon.cpp
gtest_hal_ir.cpp
gtest_hal_rgb.cpp
gtest_hal_thermal.cpp
gtest_hal_touchscreen.cpp
gtest_hal_usb_client.cpp
gtest_hal_gadget.cpp

Change-Id: I20a155136b21e6b2a4a86daeb24f2592dc281b22
Signed-off-by: lokilee73 <changjoo.lee@samsung.com>