ARM: SPEAr: Remove unused empty files

Few empty files (spear1310_misc_regs.h and spear1340_misc_regs.h) are created by
commit b31e2372 "SPEAr13xx: Add header files".

Don't know how they got added, obviously my fault :)
But nobody could even catch them in reviews.

Remove them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>