arm64/sysreg: Add definition of ISR_EL1

Add a definition of ISR_EL1 as per DDI0487I.a. This register was not
previously defined in sysreg.h, no functional changes.
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-isr-el1-v2-2-89f7073a1ca9@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/tools/sysreg

@@ -1843,6 +1843,16 @@ Res0	15:8
 Field	7:0	LR
 EndSysreg
 
+Sysreg	ISR_EL1	3	0	12	1	0
+Res0	63:11
+Field	10	IS
+Field	9	FS
+Field	8	A
+Field	7	I
+Field	6	F
+Res0	5:0
+EndSysreg
+
 Sysreg	ICC_NMIAR1_EL1	3	0	12	9	5
 Res0	63:24
 Field	23:0	INTID