backup: bug fix for improper struct dirent usage

Between Minix 3.1.2 and Minix 3.1.3, the d_name member of struct
dirent was reduced from 61 characters to 1 character. backup(8)
blindly copies the result of readdir() into an array of dirent
structs. As a consequence, the structs in the array only contain
the first letter of the name and the name string was not null
terminated. This caused the backup utility to always fail.

Remedy the situation by adding room for the full d_name.

Change-Id: I2a7b4630f1bb727825a95a6095a7a543fc2f08f6
mmio: add 16-bit variants of read/write/set

Change-Id: If4fb5585865768daa151bd4aa343ac5c84d2e9c3
i2c: general clean-up

Implement changes based on Kees comments on the code review:
	http://gerrit-minix.few.vu.nl/#/c/676/

Changes:
 - use spin API instead of micro_delay() for busy-wait loops.
 - use read16/write16/set16 from mmio.h to access I2C registers.
 - reduce the timeout for soft reset.
 - in read/write, don't mix variable declaration and initialization.
 - after transfer, wait for access ready instead of blindly delaying.
 - rename constants am335x, dm37xx to AM335X_I2C_BUS, DM37XX_I2C_BUS.
 - rename ADDRESS_MASK to MAX_I2C_SA_MASK for clairity.
 - rename omap_i2c_claim_bus() to omap_i2c_bus_is_free().

Change-Id: Ic221e6134e024ea0a6690f21cff208a728286948
mined: K&R to ANSI, fix function sigs & warnings

 - Re-write function declarations from K&R style to ANSI style.
 - Change declaration of write_char(), S(), in_list() to match ptotos.
 - Resolve clang warnings about assignments in conditionals.

Change-Id: I61624b18afbefe1ff29941233d274bd6c0f12520
loadramdisk: bug fix for bad fprintf() format

An fprintf() has two %s formats but only one additional argument.

Include the name of the device file in the fprintf() call to
balance the arguments and format.

Change-Id: I62e702cf0bc9935897c2f85b0acc3b62b41d654a