[PATCH] Kconfig fix (BLK_DEV_FD dependencies)

Sanitized and fixed floppy dependencies: split the messy dependencies for
BLK_DEV_FD by introducing a new symbol (ARCH_MAY_HAVE_PC_FDC), making
BLK_DEV_FD depend on that one and taking declarations of ARCH_MAY_HAVE_PC_FDC
to arch/*/Kconfig.  While we are at it, fixed several obvious cases when
BLK_DEV_FD should have been excluded (architectures lacking asm/floppy.h
are *not* going to have floppy.c compile, let alone work).

If you can come up with better name for that ("this architecture might
have working PC-compatible floppy disk controller"), you are more than
welcome - just s/ARCH_MAY_HAVE_PC_FDC/your_prefered_name/g in the patch
below...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/mips/Kconfig

@@ -4,6 +4,11 @@ config MIPS
 	# Horrible source of confusion.  Die, die, die ...
 	select EMBEDDED
 
+# shouldn't it be per-subarchitecture?
+config ARCH_MAY_HAVE_PC_FDC
+	bool
+	default y
+
 mainmenu "Linux/MIPS Kernel Configuration"
 
 source "init/Kconfig"