arm64: v8.3: Support for Javascript conversion instruction

ARMv8.3 adds support for a new instruction to perform conversion
from double precision floating point to integer  to match the
architected behaviour of the equivalent Javascript conversion.
Expose the availability via HWCAP and MRS emulation.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index ac24b6e..cbb3143 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -156,6 +156,9 @@
 #define ID_AA64ISAR0_SHA1_SHIFT		8
 #define ID_AA64ISAR0_AES_SHIFT		4
 
+/* id_aa64isar1 */
+#define ID_AA64ISAR1_JSCVT_SHIFT	12
+
 /* id_aa64pfr0 */
 #define ID_AA64PFR0_GIC_SHIFT		24
 #define ID_AA64PFR0_ASIMD_SHIFT		20