arc: add _ARC_V2_IRQ_TRIGGER inline function
arc: add _ARC_V2_IRQ_TRIGGER inline function

ARC interrupts can be either level or pulse.

Level interrupts remain asserted until the interrupt service routine
clears the interrupt at the peripheral. This is the default and most
common case.

Pulse interrupts have an extra flip-flop that converts a pulse to a 
level. The ARC auto-clears this level as the interrupt service routine
is entered. As such, an interrupt handler for a pulse interrupt need
not clear the interrupt.
It is the rare device that uses pulse interrupts.

Nothing currently calls this inline function so ARC interrupts are
LEVEL by default.

(see ZEP-83)

Change-Id: I09ef86aae1926c1327e82ff99c2f8aa7eabde684
Signed-off-by: Chuck Jordan <c464ed312fa6f818297227c7e5018fc9f4bd95ad@synopsys.com>

fractalclone/zephyr-riscv,finikorg/zephyr,erwango/zephyr,nashif/zephyr,runchip/zephyr-cc3220,mbolivar/zephyr,galak/zephyr,runchip/zephyr-cc3200,tidyjiang8/zephyr-doc,sharronliu/zephyr,bigdinotech/zephyr,sharronliu/zephyr,nashif/zephyr,explora26/zephyr,punitvara/zephyr,holtmann/zephyr,pklazy/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,galak/zephyr,runchip/zephyr-cc3200,finikorg/zephyr,GiulianoFranchetto/zephyr,runchip/zephyr-cc3200,aceofall/zephyr-iotos,explora26/zephyr,mbolivar/zephyr,fractalclone/zephyr-riscv,ldts/zephyr,bigdinotech/zephyr,holtmann/zephyr,fbsder/zephyr,finikorg/zephyr,ldts/zephyr,Vudentz/zephyr,mbolivar/zephyr,aceofall/zephyr-iotos,zephyriot/zephyr,sharronliu/zephyr,explora26/zephyr,holtmann/zephyr,erwango/zephyr,fractalclone/zephyr-riscv,Vudentz/zephyr,erwango/zephyr,explora26/zephyr,punitvara/zephyr,bigdinotech/zephyr,bigdinotech/zephyr,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,erwango/zephyr,bboozzoo/zephyr,kraj/zephyr,nashif/zephyr,sharronliu/zephyr,sharronliu/zephyr,explora26/zephyr,runchip/zephyr-cc3220,punitvara/zephyr,pklazy/zephyr,holtmann/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,bigdinotech/zephyr,kraj/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,fbsder/zephyr,rsalveti/zephyr,fractalclone/zephyr-riscv,GiulianoFranchetto/zephyr,kraj/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,mbolivar/zephyr,rsalveti/zephyr,kraj/zephyr,tidyjiang8/zephyr-doc,runchip/zephyr-cc3220,pklazy/zephyr,bboozzoo/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,bboozzoo/zephyr,tidyjiang8/zephyr-doc,zephyrproject-rtos/zephyr,galak/zephyr,fbsder/zephyr,pklazy/zephyr,zephyriot/zephyr,aceofall/zephyr-iotos,rsalveti/zephyr,ldts/zephyr,Vudentz/zephyr,pklazy/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,bboozzoo/zephyr,holtmann/zephyr,Vudentz/zephyr,mbolivar/zephyr,Vudentz/zephyr,fbsder/zephyr,tidyjiang8/zephyr-doc,bboozzoo/zephyr,runchip/zephyr-cc3200,galak/zephyr,nashif/zephyr,zephyriot/zephyr,runchip/zephyr-cc3220,rsalveti/zephyr,runchip/zephyr-cc3220,punitvara/zephyr,zephyriot/zephyr,zephyriot/zephyr,erwango/zephyr,punitvara/zephyr,fbsder/zephyr,runchip/zephyr-cc3200,fractalclone/zephyr-riscv,finikorg/zephyr,rsalveti/zephyr,tidyjiang8/zephyr-doc