powerpc: Disable CPU unknown by CLANG when CC_IS_CLANG

CLANG only knows the following CPUs:

generic, 440, 450, 601, 602, 603, 603e, 603ev, 604, 604e, 620, 630,
g3, 7400, g4, 7450, g4+, 750, 8548, 970, g5, a2, e500, e500mc, e5500,
power3, pwr3, power4, pwr4, power5, pwr5, power5x, pwr5x, power6,
pwr6, power6x, pwr6x, power7, pwr7, power8, pwr8, power9, pwr9,
power10, pwr10, powerpc, ppc, ppc32, powerpc64, ppc64, powerpc64le,
ppc64le, futur

Disable other ones when CC_IS_CLANG.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e62892e32c14a7a5738c597e39e0082cb0abf21c.1675335659.git.christophe.leroy@csgroup.eu

arch/powerpc/platforms/Kconfig.cputype

@@ -143,6 +143,7 @@ config POWERPC_CPU
 config CELL_CPU
 	bool "Cell Broadband Engine"
 	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
+	depends on !CC_IS_CLANG
 	select PPC_64S_HASH_MMU
 
 config PPC_970_CPU
@@ -187,11 +188,13 @@ config E5500_CPU
 config E6500_CPU
 	bool "Freescale e6500"
 	depends on PPC64 && PPC_E500
+	depends on !CC_IS_CLANG
 	select PPC_HAS_LBARX_LHARX
 
 config 405_CPU
 	bool "40x family"
 	depends on 40x
+	depends on !CC_IS_CLANG
 
 config 440_CPU
 	bool "440 (44x family)"
@@ -200,22 +203,27 @@ config 440_CPU
 config 464_CPU
 	bool "464 (44x family)"
 	depends on 44x
+	depends on !CC_IS_CLANG
 
 config 476_CPU
 	bool "476 (47x family)"
 	depends on PPC_47x
+	depends on !CC_IS_CLANG
 
 config 860_CPU
 	bool "8xx family"
 	depends on PPC_8xx
+	depends on !CC_IS_CLANG
 
 config E300C2_CPU
 	bool "e300c2 (832x)"
 	depends on PPC_BOOK3S_32
+	depends on !CC_IS_CLANG
 
 config E300C3_CPU
 	bool "e300c3 (831x)"
 	depends on PPC_BOOK3S_32
+	depends on !CC_IS_CLANG
 
 config G4_CPU
 	bool "G4 (74xx)"