jtag: use proper format with uint32_t

jtag: use proper format with uint32_t

Modify the format strings to properly handle uint32_t data types.

Change the prototype of detect_swo_freq_and_prescaler() in
'jlink.c' to avoid an implicit cast in the caller function.

Change the type of the variable retlen in some functions in
'usb_blaster.c' to properly pass their pointer to the local read
and write functions.

Use the proper parser COMMAND_PARSE_NUMBER(u32, ...).

Change-Id: I5227dbce04ee59881f173724db90790b7b9cc7af
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5815
Tested-by: jenkins