ARM: remove bogus cp_delay() function

ARM: remove bogus cp_delay() function

The cp_delay() function was introduced because of a missing 'volatile'
attribute to the 'asm' statement in get_cr() which led to the 'mrc'
instruction in get_cr() being optimised out eventually.
This has been fixed in commit 53fd4b8c22bb ("arm: mmu: Add missing volatile for reading SCTLR register")
but the bogus cp_delay() function which was introduced as a workaround
for the malfunctioning get_cr() was never removed.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>