[make] add -Wstrict-prototypes and clean up old C style prototypes

replace all built versions of foo(); with foo(void);

(cherry picked from commit 7643bc28c3a99108a85828f1796f1bc3b07ddde5)
[backport to old Qualcomm LK]

arch/arm/include/arch/arm.h

@@ -32,7 +32,8 @@ extern "C" {
 
 void arm_context_switch(vaddr_t *old_sp, vaddr_t new_sp);
 
-static inline uint32_t read_cpsr() {
+static inline uint32_t read_cpsr(void)
+{
 	uint32_t cpsr;
 
 	__asm__ volatile("mrs   %0, cpsr" : "=r" (cpsr));

kernel/main.c

@@ -54,7 +54,7 @@ static void call_constructors(void)
 	while(ctor != &__ctor_end) {
 		void (*func)(void);
 
-		func = (void (*)())*ctor;
+		func = (void (*)(void))*ctor;
 
 		func();
 		ctor++;

makefile

@@ -52,7 +52,7 @@ endif
 
 INCLUDES := -I$(BUILDDIR) -Iinclude
 CFLAGS := -O2 -g -finline -W -Wall -Wno-multichar -Wno-unused-parameter -Wno-unused-function $(LKLE_CFLAGS) -include $(CONFIGHEADER)
-CFLAGS += -fno-common
+CFLAGS += -fno-common -Wstrict-prototypes
 #CFLAGS += -Werror
 
 ifeq ($(SIGNED_KERNEL),1)

platform/armemu/debug.c

@@ -93,7 +93,7 @@ void debug_set_trace_level(int trace_type, int level)
 	*REG32(DEBUG_SET_TRACELEVEL_CPU + trace_type * 4) = level;
 }
 
-uint32_t debug_cycle_count()
+uint32_t debug_cycle_count(void)
 {
 	return *REG32(DEBUG_CYCLE_COUNT);
 }