Add InstanClient on Win paths to FindOracle.cmake

Having InstanClient SDK unpacked in C:\instantclient_11_2, the lookup
seems to work:
-- ORACLE_INCLUDE_DIR = C:/instantclient_11_2/sdk/include
-- ORACLE_LIBRARIES       =
c:/instantclient_11_2/sdk/lib/msvc/ociw32.lib
C:/instantclient_11_2/sdk/lib/msvc/oraocci11.lib
C:/instantclient_11_2/sdk/lib/msvc/ociw32.lib