IntelSiliconPkg/PeiSmmAccessLib: Remove S3 requirement

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3539



PeiInstallSmmAccessPpi() currently requires the boot mode be set
to S3 to actually install gEfiPeiMmAccessPpiGuid.

This change removes this requirement in the function implementation
for two reasons:

1. Practical use cases exist to require this PPI in cases other than
   the boot mode being set to BOOT_ON_S3_RESUME.

2. It is poor API design to implicitly bury this requirement within
   a function whose responsibility is to install the PPI. The caller
   can easily place arbitrary constraints around whether to call
   based on conditions such as the boot mode being
   BOOT_ON_S3_RESUME.

Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>