chargeled compiler warnings

[ 53% 3233/6072] target C++: chargeled <= device/htc/pme/recovery/chargeled/chargeled.cpp
device/htc/pme/recovery/chargeled/chargeled.cpp:61:7: warning: ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]
{ "Unknown", BATTERY_STATUS_UNKNOWN },
^
device/htc/pme/recovery/chargeled/chargeled.cpp:62:7: warning: ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]
{ "Charging", BATTERY_STATUS_CHARGING },
^
device/htc/pme/recovery/chargeled/chargeled.cpp:63:7: warning: ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]
{ "Discharging", BATTERY_STATUS_DISCHARGING },
^
device/htc/pme/recovery/chargeled/chargeled.cpp:64:7: warning: ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]
{ "Not charging", BATTERY_STATUS_NOT_CHARGING },
^
device/htc/pme/recovery/chargeled/chargeled.cpp:65:7: warning: ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]
{ "Full", BATTERY_STATUS_FULL },
^
5 warnings generated.