ARM: put types.h in uapi

Due to the way kbuild works, this header was unintentionally exported
back in 2013 when it was created, despite it not being in a uapi/
directory.  This is very non-intuitive behaviour by Kbuild.

However, we've had this include exported to userland for almost four
years, and searching google for "ARM types.h __UINTPTR_TYPE__" gives
no hint that anyone has complained about it.  So, let's make it
officially exported in this state.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>