pmm_hhdmfree()

we had a pmm_hhdmalloc() but not a pmm_hhdmfree(), so that interface function is now implemented

src/include/kernel/pmm.h

@@ -6,6 +6,7 @@
 void pmm_init();
 void* pmm_alloc(size_t);
 void* pmm_hhdmalloc(size_t);
+void pmm_hhdmfree(void*, size_t);
 void pmm_free(void*, size_t);
 void pmm_setused(void*, size_t);
 

src/sys/mm/pmm.c

@@ -137,6 +137,10 @@ void* pmm_alloc(size_t count){
 
 }
 
+void pmm_hhdmfree(void* addr, size_t count){
+	pmm_free(addr - (size_t)limine_hhdm_offset, count);
+}
+
 void* pmm_hhdmalloc(size_t count){
 	void* alloc = pmm_alloc(count);
 	if(!alloc) return NULL;