MIPS: Make __{,n,u}delay declarations match definitions and generic delay.h

At some recent point arch/mips/include/asm/delay.h has started being
included into csrc-octeon.c where the __?delay() functions are defined.
This causes a compile failure due to conflicting declarations and
definitions of the functions.

It turns out that the generic definitions in arch/mips/lib/delay.c also
conflict.

Proposed fix: Declare the functions to take unsigned long parameters
just like asm-generic (and x86) does. Update __delay to agree
(__ndelay and __udelay need no change).

Bonus: Get rid of 'inline' from __delay() definition, as it is globally
visible, and the compiler should be making this decision itself (it does
in fact inline the function without being told to).

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix potencial build error in <asm/delay.h>

<asm/delay.h> will break if HZ isn't defined. In 2.6.26 and later we're
usually lucky ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix typo resulting in far too long ndelay times.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Outline udelay and fix a few issues.

Outlining fixes the issue were on certain CPUs such as the R10000 family
the delay loop would need an extra cycle if it overlaps a cacheline
boundary.

The rewrite also fixes build errors with GCC 4.4 which was changed in
way incompatible with the kernel's inline assembly.

Relying on pure C for computation of the delay value removes the need for
explicit. The price we pay is a slight slowdown of the computation - to
be fixed on another day.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Move headfiles to new location below arch/mips/include

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>