ppc: Zap HWW1U1A board

This is the only used of CONFIG_SPI_X macro, just zap this.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Tom Rini <trini@ti.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Heiko Schocher <hs@denx.de>