ARM: 9118/1: div64: Remove always-true __div64_const32_is_OK() duplicate

Since commit cafa0010 ("Raise the minimum required gcc version
to 4.6"), the kernel can no longer be compiled using gcc-3.
Hence __div64_const32_is_OK() is always true.

Moreover, __div64_const32_is_OK() is defined in the same way in
include/asm-generic/div64.h, so the ARM-specific definition can be
removed regardless.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>