cpu-exec: Purge all uses of ENV_GET_CPU()

Remove un-needed usages of ENV_GET_CPU() by converting the APIs to use
CPUState pointers and retrieving the env_ptr as minimally needed.

Scripted conversion for target-* change:

for I in target-*/cpu.h; do
    sed -i \
    's/\(^int cpu_[^_]*_exec(\)[^ ][^ ]* \*s);$/\1CPUState *cpu);/' \
    $I;
done

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-mips/cpu.h b/target-mips/cpu.h
index 474a0e3..075c561 100644
--- a/target-mips/cpu.h
+++ b/target-mips/cpu.h
@@ -746,7 +746,7 @@
  */
 #define CPU_INTERRUPT_WAKE CPU_INTERRUPT_TGT_INT_0
 
-int cpu_mips_exec(CPUMIPSState *s);
+int cpu_mips_exec(CPUState *cpu);
 void mips_tcg_init(void);
 MIPSCPU *cpu_mips_init(const char *cpu_model);
 int cpu_mips_signal_handler(int host_signum, void *pinfo, void *puc);