target/hppa: Use env_cpu, env_archcpu

Cleanup in the boilerplate that each target must define.
Replace hppa_env_get_cpu with env_archcpu.  The combination
CPU(hppa_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/target/hppa/op_helper.c b/target/hppa/op_helper.c
index 952e97a..04d23c1 100644
--- a/target/hppa/op_helper.c
+++ b/target/hppa/op_helper.c
@@ -29,8 +29,7 @@
 
 void QEMU_NORETURN HELPER(excp)(CPUHPPAState *env, int excp)
 {
-    HPPACPU *cpu = hppa_env_get_cpu(env);
-    CPUState *cs = CPU(cpu);
+    CPUState *cs = env_cpu(env);
 
     cs->exception_index = excp;
     cpu_loop_exit(cs);
@@ -38,8 +37,7 @@
 
 void QEMU_NORETURN hppa_dynamic_excp(CPUHPPAState *env, int excp, uintptr_t ra)
 {
-    HPPACPU *cpu = hppa_env_get_cpu(env);
-    CPUState *cs = CPU(cpu);
+    CPUState *cs = env_cpu(env);
 
     cs->exception_index = excp;
     cpu_loop_exit_restore(cs, ra);
@@ -630,7 +628,7 @@
 #ifndef CONFIG_USER_ONLY
 void HELPER(write_interval_timer)(CPUHPPAState *env, target_ureg val)
 {
-    HPPACPU *cpu = hppa_env_get_cpu(env);
+    HPPACPU *cpu = env_archcpu(env);
     uint64_t current = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     uint64_t timeout;