MIPS: update MIPS_L1_CACHE_SHIFT based on MIPS_L1_CACHE_SHIFT_<N>

All platforms that require a special MIPS_L1_CACHE_SHIFT value have been
updated, such that we can now make MIPS_L1_CACHE_SHIFT default to the
appropriate integer value based on the select MIPS_L1_CACHE_SHIFT_<N>
variable.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>

arch/mips/Kconfig

@@ -1110,9 +1110,10 @@ config MIPS_L1_CACHE_SHIFT_7
 
 config MIPS_L1_CACHE_SHIFT
 	int
-	default "4" if MACH_DECSTATION || MIKROTIK_RB532 || PMC_MSP4200_EVAL || SOC_RT288X
-	default "6" if MIPS_CPU_SCACHE
-	default "7" if SGI_IP22 || SGI_IP27 || SGI_IP28 || SNI_RM || CPU_CAVIUM_OCTEON
+	default "4" if MIPS_L1_CACHE_SHIFT_4
+	default "5" if MIPS_L1_CACHE_SHIFT_5
+	default "6" if MIPS_L1_CACHE_SHIFT_6
+	default "7" if MIPS_L1_CACHE_SHIFT_7
 	default "5"
 
 config HAVE_STD_PC_SERIAL_PORT