[mlir][math] Expand math.ceilf to truncate, compares and increments

Ceilf are pushed directly to libm. This is problematic for
situations where libm is not available. This patch will break down
a ceilf function to truncate followed by an increment if the
truncated value is smaller than the input value.

Reviewed By: rsuderman

Differential Revision: https://reviews.llvm.org/D147974