ARM: imx: fix dependencies on imx7ulp

ARM: imx: fix dependencies on imx7ulp

The i.MX7D configuration was reworked, but that change did
not get propagated into the newly added i.MX7ULP, which now
produces a Kconfig warning:

WARNING: unmet direct dependencies detected for HAVE_ARM_ARCH_TIMER
  Depends on [n]: CPU_V7 [=n]
  Selected by [y]:
  - SOC_IMX7ULP [=y] && ARCH_MXC [=y] && (ARCH_MULTI_V7 [=n] || ARM_SINGLE_ARMV7M [=y])

Change it to work the same way as i.MX7D.

Fixes: 1a1f919eb52e ("ARM: imx: Provide support for NXP i.MX7D Cortex-M4")
Fixes: de70d0e9d43d ("ARM: imx: add initial support for imx7ulp")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>