ARM: l2c: zynq: remove cache size override

The cache size should already be present in the L2 cache auxiliary
control register: it is part of the integration process to configure
the hardware IP.  Most platforms get this right, yet still many
cargo-cult program, and assume that they always need specifying to
the L2 cache code.  Remove them so we can find out which really need
this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>