libcamera: utils: Add alignUp and alignDown functions

Add to libcamera utils library two functions to round up or down a
value to an alignment and add a test in test/utils.cpp for the two
new functions.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/internal/utils.h

@@ -200,6 +200,16 @@ details::StringSplitter split(const std::string &str, const std::string &delim);
 std::string libcameraBuildPath();
 std::string libcameraSourcePath();
 
+constexpr unsigned int alignDown(unsigned int value, unsigned int alignment)
+{
+	return value / alignment * alignment;
+}
+
+constexpr unsigned int alignUp(unsigned int value, unsigned int alignment)
+{
+	return (value + alignment - 1) / alignment * alignment;
+}
+
 } /* namespace utils */
 
 } /* namespace libcamera */