ARM: shmobile: defconfig: Refresh for v5.0-rc1

- Move SoC config options (moved in commit 062887bf ("ARM:
    shmobile: Move SoC Kconfig symbols to drivers/soc/renesas/")),
  - Move PCI config options (moved in commit eb01d42a ("PCI:
    consolidate PCI config entry in drivers/pci")),
  - Drop CONFIG_I2C_MUX=y (auto-enabled since commit ea6b13e9
    ("drm/bridge/sii902x: Add missing dependency on I2C_MUX")),
  - Drop CONFIG_SH_DMAE=y (no longer selectable since commit
    a1978861 ("dmaengine: sh: Remove R-Mobile APE6 support")),
  - Drop CONFIG_ARM_UNWIND (auto-enabled since commit f9b58e8c
    ("ARM: 8800/1: use choice for kernel unwinders")).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>