scripts: extract_dts_includes: Fix extract_cells for a list
scripts: extract_dts_includes: Fix extract_cells for a list

If we had something like:

gpios = <&gpiod 13 GPIO_INT_ACTIVE_LOW
         &gpiod 14 GPIO_INT_ACTIVE_LOW>;

The script blows up in extract_cells.  While extract_cells attempted to
handle more than a single item in such a list, it didn't manipulate the
prop list for the recursive calls properly.

Since we pop off items from the prop list as we use them we can easily
pass the prop list to the rescurive call to fix things.

Besides, if alias is defined for the node, indexed aliases defines are
generated:
 #define GPIO_LEDS_0_GPIO_FLAGS_0 4
 #define GPIO_LEDS_0_GPIO_FLAGS_1 0
 #define GPIO_LEDS_0_GPIO_PIN_0   5
 #define GPIO_LEDS_0_GPIO_PIN_1   6
 #define LED1_GPIO_FLAGS_0 GPIO_LEDS_0_GPIO_FLAGS_0
 #define LED1_GPIO_FLAGS_1 GPIO_LEDS_0_GPIO_FLAGS_1
 #define LED1_GPIO_PIN_0 GPIO_LEDS_0_GPIO_PIN_0
 #define LED1_GPIO_PIN_1 GPIO_LEDS_0_GPIO_PIN_1

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

zephyriot/zephyr,punitvara/zephyr,ldts/zephyr,kraj/zephyr,mbolivar/zephyr,punitvara/zephyr,nashif/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,explora26/zephyr,finikorg/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,punitvara/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,kraj/zephyr,zephyriot/zephyr,ldts/zephyr,punitvara/zephyr,explora26/zephyr,nashif/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,galak/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,Vudentz/zephyr,explora26/zephyr,kraj/zephyr,ldts/zephyr,Vudentz/zephyr,kraj/zephyr,finikorg/zephyr,mbolivar/zephyr,mbolivar/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyriot/zephyr,zephyriot/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,galak/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,ldts/zephyr,explora26/zephyr