Enable force platform minnowboard turbot

Compile error would result if force minnowboard max. This is
because mraa_intel_minnowboard_byt_compatible signature requires
bool option for max or turbot board variations. This patch allows
user to force platform for either max or turbot without compile
error.

Author: tripzero

src/CMakeLists.txt

@@ -68,6 +68,8 @@ if (NOT ${MRAAPLATFORMFORCE} STREQUAL "ALL")
     set (mraa_LIB_X86_SRCS_NOAUTO ${PROJECT_SOURCE_DIR}/src/x86/x86.c ${PROJECT_SOURCE_DIR}/src/x86/intel_edison_fab_c.c)
   elseif (${MRAAPLATFORMFORCE} STREQUAL "MRAA_INTEL_MINNOWBOARD_MAX")
     set (mraa_LIB_X86_SRCS_NOAUTO ${PROJECT_SOURCE_DIR}/src/x86/x86.c ${PROJECT_SOURCE_DIR}/src/x86/intel_minnow_byt_compatible.c)
+  elseif (${MRAAPLATFORMFORCE} STREQUAL "MRAA_INTEL_MINNOWBOARD_TURBOT")
+    set (mraa_LIB_X86_SRCS_NOAUTO ${PROJECT_SOURCE_DIR}/src/x86/x86.c ${PROJECT_SOURCE_DIR}/src/x86/intel_minnow_byt_compatible.c)
   elseif (${MRAAPLATFORMFORCE} STREQUAL "MRAA_INTEL_NUC5")
     set (mraa_LIB_X86_SRCS_NOAUTO ${PROJECT_SOURCE_DIR}/src/x86/x86.c ${PROJECT_SOURCE_DIR}/src/x86/intel_nuc5.c)
   elseif (${MRAAPLATFORMFORCE} STREQUAL "MRAA_INTEL_SOFIA_3GR")

src/x86/x86.c

@@ -131,7 +131,9 @@ mraa_x86_platform()
     #elif defined(xMRAA_INTEL_DE3815)
     plat = mraa_intel_de3815();
     #elif defined(xMRAA_INTEL_MINNOWBOARD_MAX)
-    plat = mraa_intel_minnowboard_byt_compatible();
+    plat = mraa_intel_minnowboard_byt_compatible(0);
+    #elif defined(xMRAA_INTEL_MINNOWBOARD_TURBOT)
+    plat = mraa_intel_minnowboard_byt_compatible(1);
     #elif defined(xMRAA_INTEL_GALILEO_GEN1)
     plat = mraa_intel_galileo_rev_d();
     #elif defined(xMRAA_INTEL_NUC5)