[ARM,MVE] Integer-type nitpicks in MVE intrinsics.

A few integer types in the ACLE definitions of MVE intrinsics are
given as 'int' or 'unsigned' instead of <stdint.h> fixed-size types
like uint32_t. Usually these are the ones where the size isn't that
important, such as immediate offsets in loads (which have a range
limited by the instruction encoding) or the carry flag in vadcq which
can only be 0 or 1 anyway.

With this change, <arm_mve.h> follows that exact type naming, so that
the function prototypes look identical to the ones in ACLE, instead of
replacing int and unsigned with int32_t and uint32_t.

Reviewers: dmgreen

Subscribers: kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69790