i2c: pxa: hide unused icr_bits[] variable

The function using this is hidden in an #ifdef, so the variable
needs the same one for a clean W=1 build:

drivers/i2c/busses/i2c-pxa.c:327:26: error: 'icr_bits' defined but not used [-Werror=unused-const-variable=]

Fixes: d6a7b5f8 ("[ARM] 4827/1: fix two warnings in drivers/i2c/busses/i2c-pxa.c")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>