Since the RA2L1 uses the macro "ICU_EVENT" instead of
"ELC_EVENT" (which is currently used) to input into
the IELSR register, the ek_ra2l1 board cannot assign
any interrupts for any driver.
This commit aim to correct the Event macro to input correct
value for IELSR register on all the Renesas SoC by using
"BSP_PRV_IELS_ENUM" macro.
Signed-off-by: Khoa Nguyen <khoa.nguyen.xh@renesas.com>