[hw, hjson] SRAM Controller use `multibits.h` in register desc

Signed-off-by: Silvestrs Timofejevs <silvestrst@lowrisc.org>
diff --git a/hw/ip/sram_ctrl/data/sram_ctrl.hjson b/hw/ip/sram_ctrl/data/sram_ctrl.hjson
index 20c31cc..c8cca73 100644
--- a/hw/ip/sram_ctrl/data/sram_ctrl.hjson
+++ b/hw/ip/sram_ctrl/data/sram_ctrl.hjson
@@ -205,10 +205,10 @@
             name: "EN",
             mubi: true,
             desc: '''
-                  Write kMubi4True to this field to enable execution from SRAM.
+                  Write kMultiBitBool4True to this field to enable execution from SRAM.
                   Note that this register only takes effect if the EN_SRAM_IFETCH chicken switch
-                  in the OTP HW_CFG partition is set to kMubi8True. Otherwise execution from SRAM cannot be
-                  enabled via this register.
+                  in the OTP HW_CFG partition is set to kMultiBitBool8True. Otherwise execution
+                  from SRAM cannot be enabled via this register.
                   ''',
             resval: false
           },