libpayload: Add div_round_up() function

The lack of a div_round_up() function in libpayload keeps being a
problem for payloads and has already caused us to sprinkle numerous
less-readable ALIGN_UP(n, d) / d throughout depthcharge. Let's add this
so we can avoid adding any more and then maybe cocchinelle them all over
later.

BRANCH=None
BUG=None
TEST=None

Change-Id: I241a52770a0edcf7003b48a81875b3fa0cb7ed53
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a3f9514f9cfd325cc3c4b542020574b605fac935
Original-Change-Id: Ia55bd4bc52ab8a249b4854e40727cf6917af7b30
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/273050
Original-Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10392
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/include/libpayload.h

@@ -66,6 +66,8 @@
 #define MAX(a,b) ((a) > (b) ? (a) : (b))
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
+static inline u32 div_round_up(u32 n, u32 d) { return n + d - 1 / d; }
+
 #define LITTLE_ENDIAN	1234
 #define BIG_ENDIAN	4321