x86: p2sb: Drop 'apl' prefix

Drop the Apollo Lake prefix 'apl' from the functions, types and
variables in the P2SB driver.

The P2SB is not Apollo Lake specific, and as such it was moved in
commit 2999846c ("x86: Move P2SB from Apollo Lake to a more generic
location") from the Apollo Lake folder to the intel_common folder.

Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>