feat(gic): add APIs to raise NS and S-EL1 SGIs

This patch adds two helper functions:
 - plat_ic_raise_ns_sgi to raise a NS SGI
 - plat_ic_raise_s_el1_sgi to raise a S-EL1 SGI

Signed-off-by: Florian Lugou <florian.lugou@provenrun.com>
Change-Id: I6f262dd1da1d77fec3f850eb74189e726b8e24da
diff --git a/include/arch/aarch64/arch.h b/include/arch/aarch64/arch.h
index 3a2a032..8d3e31d 100644
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@@ -79,6 +79,7 @@
  ******************************************************************************/
 #define ICC_IGRPEN1_EL1		S3_0_C12_C12_7
 #define ICC_SGI1R		S3_0_C12_C11_5
+#define ICC_ASGI1R		S3_0_C12_C11_6
 #define ICC_SRE_EL1		S3_0_C12_C12_5
 #define ICC_SRE_EL2		S3_4_C12_C9_5
 #define ICC_SRE_EL3		S3_6_C12_C12_5