If NIOS2_CMDLINE_IGNORE_DTB is selected but CMDLINE_BOOL isn't and thus
CONFIG_CMDLINE is not defined, the build fails with the following error:

arch/nios2/kernel/setup.c: In function 'nios2_boot_init':
arch/nios2/kernel/setup.c:131:30: error: 'CONFIG_CMDLINE' undeclared
(first use in this function)
   strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);

This can be reproduced using randconfig with KCONFIG_SEED=0xE5B8749E, i.e.
'make KCONFIG_SEED=0xE5B8749E ARCH=nios2 randconfig'.

Fix this by letting NIOS2_CMDLINE_IGNORE_DTB depend on CMDLINE_BOOL, so we
actually have a default kernel command string to fall back to.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NLey Foon Tan <lftan@altera.com>

kernel/time/Kconfig expects that NR_CPUS is defined.

This fixes the following config warning:
"kernel/time/Kconfig:163:warning: range is invalid"

Follow 4cbbbb43 ("microblaze: Fix missing NR_CPUS in menuconfig")
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NLey Foon Tan <lftan@altera.com>

This patch adds Makefile and Kconfig files required for building a
nios2 kernel.
Signed-off-by: NLey Foon Tan <lftan@altera.com>