am7xxx: bump _POSIX_C_SOURCE to 200112L for lroundf()

The library code uses lroundf() from math.h but some compilers may warn
about an implicit definition of it, so make sure it it actually
available by following the requirements from the LROUND(3) man page.

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index f743b1a..7e914f7 100644 (file)
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,5 +1,5 @@
 add_definitions("-D_BSD_SOURCE") # for htole32()
-add_definitions("-D_POSIX_C_SOURCE=199309L") # for nanosleep()
+add_definitions("-D_POSIX_C_SOURCE=200112L") # for nanosleep() and lroundf()
 
 # Find packages needed to build library
 find_package(libusb-1.0 REQUIRED)