clk: aspeed: ast2700: select AUXILIARY_BUS

The AST2700 clock driver also exposes the SoC reset controller: it hands
its register base to a reset auxiliary device via
devm_auxiliary_device_create(), which the separate ASPEED reset driver
(RESET_ASPEED) then binds to. That create call needs the auxiliary bus
core (AUXILIARY_BUS), not the reset driver itself, but COMMON_CLK_AST2700
does not select AUXILIARY_BUS.

It builds today only because RESET_ASPEED selects AUXILIARY_BUS and is
normally enabled alongside the clock driver. On a randconfig with
COMMON_CLK_AST2700=y and RESET_ASPEED=n, nothing pulls the auxiliary bus
in and the kernel fails to link:

  ld: drivers/clk/aspeed/clk-ast2700.o: in function `ast2700_soc_clk_probe':
  clk-ast2700.c:(.text+0x147c): undefined reference to `__devm_auxiliary_device_create'

Select AUXILIARY_BUS directly, as other clock drivers that create
auxiliary devices do, so it builds regardless of the reset driver.

Fixes: fdc1eb624d ("clk: aspeed: add AST2700 clock driver")
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Brian Masney <bmasney@redhat.com>

drivers/clk/aspeed/Kconfig

@@ -15,6 +15,7 @@ config COMMON_CLK_ASPEED
 config COMMON_CLK_AST2700
         bool "Clock driver for AST2700 SoC"
         depends on ARCH_ASPEED || COMPILE_TEST
+        select AUXILIARY_BUS
         help
           This driver provides support for clock on AST2700 SoC.
           The driver is responsible for managing the various clocks required