treewide: fix declarations of functions with empty parameter lists

According to C99:

    The empty list in a function declarator that is not part of a definition of
    that function specifies that no information about the number or types of the
    parameters is supplied.

This means gcc is happy with the following code, which is undesirable.

    void foo();    /* declaration with an empty parameter list */

    void bar() {
        foo();     /* OK */
        foo(1);    /* OK */
        foo(1, 2); /* OK */
    }

This patch fixes declarations of functions with empty parameter lists by adding
an unnamed parameter of type void, which is the standard way to specify that a
function has no parameters. The following coccinelle script is used.

    @@
    type T;
    identifier f;
    @@

    -T f();
    +T f(void);

New compilation errors are fixed accordingly.

Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/include/arch/x86/mmu.h

@@ -311,7 +311,7 @@ struct mem_io_node {
 };
 
 void *get_paging_pml4(void);
-void *alloc_paging_struct();
+void *alloc_paging_struct(void);
 void enable_paging(void *pml4_base_addr);
 void init_paging(void);
 void map_mem(struct map_params *map_params, void *paddr, void *vaddr,

hypervisor/include/lib/mem_mgt.h

@@ -48,7 +48,7 @@ struct mem_pool {
 /* APIs exposing memory allocation/deallocation abstractions */
 void *malloc(unsigned int num_bytes);
 void *calloc(unsigned int num_elements, unsigned int element_size);
-void *alloc_page();
+void *alloc_page(void);
 void *alloc_pages(unsigned int page_num);
 void free(void *ptr);