hw/block: Drop unused nand.c

hw/block: Drop unused nand.c

The nand.c device (TYPE_NAND) is an emulation of a NAND flash memory
chip which was used by the old OMAP boards.  No current QEMU board
uses it, and although techically "-device nand,chip-id=0x6b" doesn't
error out, it's not possible to usefully use it from the command
line because the only interface it has is via calling C functions
like nand_setpins() and nand_setio().

The "config OMAP" stanza (used only by the SX1 board) is the only
thing that does "select NAND" to compile in this code, but the SX1
board doesn't actually use the NAND device.

Remove the NAND device code entirely; this is effectively leftover
cleanup from when we dropped the PXA boards and the OMAP boards
other than the sx1.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20250522142859.3122389-1-peter.maydell@linaro.org