asm: Make assembly code a module

This makes the directory/module structure more consistent.
It also avoids cluttering `main.rs`.

Signed-off-by: Joe Richey <[email protected]>

Author: josephlr

src/asm/mod.rs

@@ -0,0 +1 @@
+global_asm!(include_str!("ram64.s"));

src/main.rs

@@ -31,6 +31,7 @@ mod serial;
 #[macro_use]
 mod common;
 
+mod asm;
 mod block;
 mod bzimage;
 mod efi;
@@ -43,9 +44,6 @@ mod pci;
 mod pe;
 mod virtio;
 
-#[cfg(not(test))]
-global_asm!(include_str!("asm/ram64.s"));
-
 #[cfg(all(not(test), feature = "log-panic"))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {