IO seek offset can be set to values above UINT32_MAX, this change
changes the seek offset argument from 'ssize_t' to 'signed long long'.
Fixing platform seek functions to match the new interface update.

Change-Id: I25de83b3b7abe5f52a7b0fee36f71e60cac9cfcb
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>

Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: Ib79e2c6fe6e66dec5004701133ad6a5f4c78f2fa

Manages QSPI initialization, configuration and IO handling as boot device

Signed-off-by: Muhammad Hadi Asyrafi Abdul Halim <muhammad.hadi.asyrafi.abdul.halim@intel.com>