riscv: sifive: fix Kconfig errata warning

The SOC_SIFIVE Kconfig entry unconditionally selects ERRATA_SIFIVE.
However, ERRATA_SIFIVE depends on RISCV_ERRATA_ALTERNATIVE, which is
not set, so SOC_SIFIVE should either depend on or select
RISCV_ERRATA_ALTERNATIVE. Use 'select' here to quieten the Kconfig
warning.

WARNING: unmet direct dependencies detected for ERRATA_SIFIVE
  Depends on [n]: RISCV_ERRATA_ALTERNATIVE [=n]
  Selected by [y]:
  - SOC_SIFIVE [=y]

Fixes: 1a0e5db ("riscv: sifive: Add SiFive alternative ports")
Signed-off-by: Randy Dunlap <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: [email protected]
Cc: Vincent Chen <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: rddunlap

arch/riscv/Kconfig.socs

@@ -14,6 +14,7 @@ config SOC_SIFIVE
 	select CLK_SIFIVE
 	select CLK_SIFIVE_PRCI
 	select SIFIVE_PLIC
+	select RISCV_ERRATA_ALTERNATIVE
 	select ERRATA_SIFIVE
 	help
 	  This enables support for SiFive SoC platform hardware.