mfd: ezx-pcap: Remove unused driver

mfd: ezx-pcap: Remove unused driver

Support for the Motorola EZX phones based on Intel PXA processors was
removed in 2022, but this driver remained present in the tree. As far
as I can tell, the support was never quite functional upstream because
the board files did not actually instantiate the SPI device for the PCAP.

There are still also drivers for the various mfd cells: keys, touchscreen,
regulator and rtc, all of which are obviously orphaned as well but can
be removed separately as the Kconfig dependency now prevents them from
being enabled.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202604301209.f1YXTsIr-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Acked-by: Harald Welte <laforge@gnumonks.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260430162855.2029285-1-arnd@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>