Add compile option to disable safe mode option in boot flags

Some platforms doe not support safe mode in
set/get system boot options commands, add an compile option to disable it.
Using the below command:
./configure  --disable-boot-flag-safe-mode-support

Tested:
After adding this compile option, below command fails:

// set safe mode in set system boot options command
ipmitool raw 0 8 5 0x80 0xc
Unable to send RAW command (channel=0x0 netfn=0x0 lun=0x0 cmd=0x8 rsp=0xcc):
Invalid data field in request

Signed-off-by: Yong Li <yong.b.li@linux.intel.com>
Change-Id: Ie479a0c68a8e9fc79f99c9d4cc10cdd1e6ceb20e
diff --git a/chassishandler.cpp b/chassishandler.cpp
index 2e911f9..305897b 100644
--- a/chassishandler.cpp
+++ b/chassishandler.cpp
@@ -1327,7 +1327,9 @@
     {ipmiDefault, Source::Sources::Default}};
 
 std::map<IpmiValue, Mode::Modes> modeIpmiToDbus = {
+#ifdef ENABLE_BOOT_FLAG_SAFE_MODE_SUPPORT
     {0x03, Mode::Modes::Safe},
+#endif // ENABLE_BOOT_SAFE_MODE_SUPPORT
     {0x06, Mode::Modes::Setup},
     {ipmiDefault, Mode::Modes::Regular}};
 
@@ -1339,7 +1341,9 @@
     {Source::Sources::Default, ipmiDefault}};
 
 std::map<Mode::Modes, IpmiValue> modeDbusToIpmi = {
+#ifdef ENABLE_BOOT_FLAG_SAFE_MODE_SUPPORT
     {Mode::Modes::Safe, 0x03},
+#endif // ENABLE_BOOT_SAFE_MODE_SUPPORT
     {Mode::Modes::Setup, 0x06},
     {Mode::Modes::Regular, ipmiDefault}};