uml: remove code made redundant by CHOOSE_MODE removal

This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE.  There were lots of functions that looked like

	int foo(args){
		foo_skas(args);
	}

The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.

In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.

It turns out that usr2_handler was unused, so it is gone.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 3571703..90e24e2 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -18,7 +18,6 @@
 #include "asm/param.h"
 #include "asm/current.h"
 #include "kern_util.h"
-#include "mode.h"
 #include "os.h"
 
 int hz(void)
@@ -39,7 +38,7 @@
 static long long delta[NR_CPUS];		/* Deviation per interval */
 #endif
 
-void timer_irq(union uml_pt_regs *regs)
+void timer_irq(struct uml_pt_regs *regs)
 {
 	unsigned long long ticks = 0;
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
@@ -175,13 +174,13 @@
 	return 0;
 }
 
-void timer_handler(int sig, union uml_pt_regs *regs)
+void timer_handler(int sig, struct uml_pt_regs *regs)
 {
 	if(current_thread->cpu == 0)
 		timer_irq(regs);
 	local_irq_disable();
 	irq_enter();
-	update_process_times((regs)->skas.is_user);
+	update_process_times(regs->is_user);
 	irq_exit();
 	local_irq_enable();
 }