Include jerry-ext/handler only in nuttx-stm32f4 target (#1816)
Include jerry-ext/handler only in nuttx-stm32f4 target (#1816)

I included jerry-ext/handler only, rather than including all in jerry-ext.
Currently only handler is used in nuttx-stm32f4 repl.
nuttx.bin binary size is reduced from 231576 to 230456 bytes.

JerryScript-DCO-1.0-Signed-off-by: Sanggyu Lee sg5.lee@samsung.com
bzsolt/jerryscript,yichoi/jerryscript,bzsolt/jerryscript,yichoi/jerryscript,martijnthe/jerryscript,robertsipka/jerryscript,yichoi/jerryscript,LaszloLango/jerryscript,yichoi/jerryscript,jerryscript-project/jerryscript,jack60504/jerryscript,bsdelf/jerryscript,gabrielschulhof/jerryscript,jack60504/jerryscript,glistening/jerryscript,robertsipka/jerryscript,martijnthe/jerryscript,robertsipka/jerryscript,grgustaf/jerryscript,glistening/jerryscript,bzsolt/jerryscript,dbatyai/jerryscript,bzsolt/jerryscript,akosthekiss/jerryscript,bsdelf/jerryscript,dbatyai/jerryscript,martijnthe/jerryscript,jack60504/jerryscript,bsdelf/jerryscript,zherczeg/jerryscript,gabrielschulhof/jerryscript,robertsipka/jerryscript,LaszloLango/jerryscript,robertsipka/jerryscript,grgustaf/jerryscript,akosthekiss/jerryscript,jerryscript-project/jerryscript,jack60504/jerryscript,dbatyai/jerryscript,zherczeg/jerryscript,gabrielschulhof/jerryscript,bzsolt/jerryscript,jerryscript-project/jerryscript,zherczeg/jerryscript,akosthekiss/jerryscript,dbatyai/jerryscript,gabrielschulhof/jerryscript,grgustaf/jerryscript,grgustaf/jerryscript,dbatyai/jerryscript,bsdelf/jerryscript,glistening/jerryscript,zherczeg/jerryscript,glistening/jerryscript,jerryscript-project/jerryscript,yichoi/jerryscript,grgustaf/jerryscript,martijnthe/jerryscript,jerryscript-project/jerryscript,bsdelf/jerryscript,akosthekiss/jerryscript,LaszloLango/jerryscript,jack60504/jerryscript,grgustaf/jerryscript,akosthekiss/jerryscript,bsdelf/jerryscript,robertsipka/jerryscript,martijnthe/jerryscript,glistening/jerryscript,jack60504/jerryscript,LaszloLango/jerryscript,gabrielschulhof/jerryscript,zherczeg/jerryscript,martijnthe/jerryscript,LaszloLango/jerryscript,glistening/jerryscript