Blackfin arch: update blackfin header files to latest one in VDSP.

a) add new processor BF52x/BF54x header files
b) update blackfin BF533/BF537/BF561 header files to latest one in VDSP.
c) scrub watchdog/rtc masks from headers as we dont need/want them (too generic and the drivers dont use them)

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Roy Huang <roy.huang@analog.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>