Update cmake version to 3.15.1

[ce1adon]

This issue intends to discuss and solve the following problem:

Tensile with version >= 4.2 requires a cmake version >= 3.15.1 to build.
Do we want to:

1. allow version selection based on rocm version in Dockerfile;
2. Simply update cmake in Dockerfile to 3.15.1;
3. Other thoughts and concern

[junliume]

#961 (comment)

[atamazov]

I am not an expert in this field.

[junliume]

Closed by #961 and #978