Set noinline on kbd.c interface functions that take stack variable pointers.

Some versions of gcc have been found to inline these funcions and then
cause the calling functions to use very large stack usage.  Since
these functions are called from 16bit mode, their stack space usage is
very sensitive.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/src/kbd.c b/src/kbd.c
index 0aa8988..e9ea594 100644
--- a/src/kbd.c
+++ b/src/kbd.c
@@ -165,7 +165,7 @@
 }
 
 // GET KEYBOARD ID
-static void
+static void noinline
 handle_160a(struct bregs *regs)
 {
     u8 param[2];
@@ -231,7 +231,7 @@
     warn_unimplemented(regs);
 }
 
-static void
+static void noinline
 set_leds(void)
 {
     u8 shift_flags = (GET_BDA(kbd_flag0) >> 4) & 0x07;