lights: remove HAL_MODULE_INFO_SYM const

HAL_MODULE_INFO_SYM was declared as read-only, but
the struct is written to by libhardware.  This causes
a segfault when -Wl,-z,relro is enabled.

Fixed.

Change-Id: I209db88c745b3f1a0d0c8f08a287b7b7debd8352
diff --git a/liblight/lights.c b/liblight/lights.c
index ff8b28e..1dfcd8b 100644
--- a/liblight/lights.c
+++ b/liblight/lights.c
@@ -211,7 +211,7 @@
 	.open =  open_lights,
 };
 
-const struct hw_module_t HAL_MODULE_INFO_SYM = {
+struct hw_module_t HAL_MODULE_INFO_SYM = {
 	.tag = HARDWARE_MODULE_TAG,
 	.version_major = 1,
 	.version_minor = 0,