arm64: AArch32 user space PC alignment exception

ARMv7 does not have a PC alignment exception. ARMv8 AArch32
user space however can produce a PC alignment exception. Add
handler so that we do not dump an unexpected stack trace in
the logs.
Signed-off-by: NMark Salyzyn <salyzyn@android.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/entry.S

@@ -430,6 +430,8 @@ el0_sync_compat:
 	b.eq	el0_fpsimd_acc
 	cmp	x24, #ESR_ELx_EC_FP_EXC32	// FP/ASIMD exception
 	b.eq	el0_fpsimd_exc
+	cmp	x24, #ESR_ELx_EC_PC_ALIGN	// pc alignment exception
+	b.eq	el0_sp_pc
 	cmp	x24, #ESR_ELx_EC_UNKNOWN	// unknown exception in EL0
 	b.eq	el0_undef
 	cmp	x24, #ESR_ELx_EC_CP15_32	// CP15 MRC/MCR trap