GIC: Add API to get interrupt active status

API documentation updated.

Change-Id: I6d61785af0d5330930c709de971a904dc7c3516c
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index f00db0d..e4fb6a9 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -76,6 +76,7 @@
 int plat_ic_is_spi(unsigned int id);
 int plat_ic_is_ppi(unsigned int id);
 int plat_ic_is_sgi(unsigned int id);
+unsigned int plat_ic_get_interrupt_active(unsigned int id);
 
 /*******************************************************************************
  * Optional common functions (may be overridden)