lib: utils/irqchip: Avoid redundant writes to APLIC CLRIE register

Each APLIC CLRIE register allows disabling 32 interrupt sources at
a time by writing -1 so no need to write CLRIE register separately
for each interrupt source.

Fixes: 99792653

 ("lib: utils/irqchip: Add APLIC initialization library")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>