fixup! [Tizen] Support HW key event

fixup! [Tizen] Support HW key event

The efl-extension is not supportive on desktop.

1. no package found
>> Package efl-extension was not found in the pkg-config search path.
>> Perhaps you should add the directory containing `efl-extension.pc'
>> to the PKG_CONFIG_PATH environment variable
>> No package 'efl-extension' found

2. not declared function
>> error: ‘HWBackKeyCallback’ was not declared in this scope

Change-Id: I252aa5368723c82d13ee567a60b83b8f41241d3c
Signed-off-by: Youngsoo Choi <kenshin.choi@samsung.com>