soc: qcom: smem: a few last cleanups

This patch contains several small cleanups:
  - In qcom_smem_enumerate_partitions(), change the "local_host"
    argument to have 16 bit unsigned type
  - Also in qcom_smem_enumerate_partitions(), change the type of
    the "host0" and "host1" local variables to be u16
  - Fix error messages reporting host ids to use the right format
    specifier
  - Shorten the error messages as well, to fit on one line
  - Add a compile-time check to ensure the local host value passed
    to qcom_smem_enumerate_partitions() is in range

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>